Building  the  New  Rapid  Transit 
System  of  New  York  City 


Written  by 

FRED  LAVIS 

-  * 

From  personal  studies  for  ENGINEERING 
XEWS  with  use  of  official  data  and  photo- 
graphs of  the  Public  Service  Commission 


Design  of  the  New  Elevated  Railway  Lines 

By  MAURICE  E.  GRIEST 

Assistant  Designing  Engineer  Public  Service 
Commission  for  the  First  District 


REPRINTED  FROM  ENGINEERING  NEWS 
HILL  BUILDING.  NEW  YORK 

1915 


Copyright  1915 
HILL  PUBLISHING  CO. 


Preface 


It  is  not  generally  realized  how  huge  an  engineering  work  it  is  which  is  now- 
going  forward  in  the  city  of  Xew  York  on  extensions  of  the  underground  rapid- 
transit  railway  lines.  The  best  way  to  compare  the  relative  magnitude  of  engineering 
works  is  to  compare  the  total  expenditure  involved.  The  total  cost  of  building  and 
equipping  Xew  York's  new  rapid-transit  lines  will  be  in  the  neighborhood  of 
$366,000,000.  This  is  substantially  equal  to  the  entire  cost  of  the  Panama  Canal. 
It  is  tlfree  times  the  cost  of  the  Xew  York  barge  canal.  It  is  a  greater  amount  than 
the  total  investment  in  road  and  equipment  of  the  Chicago,  Milwaukee  &  St.  Paul 
Railway  Company,  or  the  Rock  Island,  or  the  Chicago  &  North  "Western,  or  the  Great 
Xorthern,  or  the  Xew  York  Central  &  Hudson  Eiver. 

The  building  of  underground  rapid-transit  lines  in  great  cities  is  comparatively 
a  new  development  in  engineering.  Xew  York  was  not  the  pioneer  in  this  field. 
The  first  underground  city  railway  lines  were  those  in  London,  operated  for  many 
years  with  steam  locomotives.  Underground  lines  operated  by  electric  traction  were 
luiilt  in  London  and  Budapest  and  Boston  before  the  first  Xew  York  rapid-transit 
subwav  was  in  operation.  The  development  of  the  system  in  Xew  York,  however, 
has  far  exceeded  that  in  any  other  city  of  the  world.  In  fact,  with  the  completion 
of  the  new  extensions  the  investment  in  underground  rapid-transit  lines  in  Xew  York 
will  probably  be  as  great  as  that  in  all  the  other  great  cities  of  the  world  combined. 

The  building  of  subways,  however,  is  well  recognized  to  be  the  next  step  in 
rapid-transit  development  for  the  congested  districts  of  other  large  cities.  Phila- 
delphia, Chicago,  Cleveland,  and  a  number  of  other  American  cities  have  subways 
under  way  or  projected.  The  work  carried  on  in  Xew  York  during  the  past  dozen 
ears,  and  e-|>ecially  that  now  in  progress,  has  developed  a  large  amount  of  experience 
in  .-treet  excavation  with  avoidance  to  traffic  interruption,  in  the  underpinning  of 
buildings,  and  in  the  solution  of  a  hundred  different  problems  in  connection  with 
the  work  of  construction  which  are  of  general  interest  to  the  engineering  profession. 

The  editors  of  ENGINEERING  XEWS  deemed  it  important  that  a  thorough  expert 
>tudy  of  the  Xew  York  subway  work  should  be  made  for  the  benefit  of  its  readers, 
and  arranged  with  Mr.  Fred  Lavis,  M.  Am.  Soc.  C.  E.,  to  undertake  this  work  and 
pn-MMit  the  results  in  the  columns  of  EXGIXKEIMXG  XEWS.  The  articles  written 
by  Mr.  Lavis  were  published  in  ENGINEERING  XEWS,  beginning  Oct.  1.  1914,  and 
concluding  I'er.  :J1.  In  response  to  numerous  requests  it  was  deemed  advisable  to 
reprint  these  articles  in  book  form. 

Acknowledgment  is  here  made  to  the  engineering  and  executive  staff  of  the 
Public  Service  Commission  for  the  courtesies  and  aid  extended  to  Mr.  Lavis  and 
10  the  editors  in  connection  with  the  preparation  of  the  articles  here  reprinted  and 


313151 


for  the  furnishing  of  the  drawings  and  photographs  here  reproduced.  In  fact,  it 
was  only  through  the  cooperation  of  the  engineering  staff  that  it  was  possible  to 
prepare  an  adequate  account  of  the  work. 

As  was  remarked  in  an  editorial  published  in  the  issue  of  ENGINEERING  NEWS 
in  which  Mr.  Lavis'  first  article  appeared,  the  greatest  difficulty  in  describing  a 
work  of  such  a  magnitude  is  to  know  what  to  put  in  and  what  to  leave  out.  As 
every  engineer  who  has  been  connected  with  a  great  enterprise  knows,  the  complete 
story  of  the  work,  with  all  its  problems  and  difficulties,  from  the  original  plans 
to  the  final  completion,  would  make  a  volume  of  ponderous  size.  The  attempt  of 
the  author  has  been  to  record  in  this  book  the  facts  of  chief  importance  and  interest 
to  the  engineering  profession  at  large,  and  to  do  it  in  such  a  manner  as  will  make 
the  articles  of  general  interest  and  at  the  same  time  convenient  for  reference  by 
those  who  at  any  time  may  have  to  deal  with  similar  problems. 

The  preparation  of  the  present  book  was  delayed  to  secure  the  addition  of  a 
paper  by  Mr.  Maurice  Griest,  of  the  design  staff  of  the  Public  Service  Commission, 
on  the  design  of  the  elevated  railways  which  form  part  of  the  new  rapid-transit 
system.  This  paper,  which  appears  in  ENGINEERING  XEWS  of  May  20,  1915,  is 
printed  as  the  last  chapter.  It  is  a  notable  contribution  to  the  literature  of  structural 
engineering,  being  the  first  discussion  of  elevated-railway  design  that  has  appeared 
for  15  years  or  more. 

More  than  this,  however — every  engineer  interested  in  the  extension  of  rapid 
transit  needs  to  study  this  paper.  For  some  years  fashions  have  run  to  subways, 
while  elevated  railways  have  been  under  a  cloud.  There  is  good  prospect  that 
views  will  shift  again  on  these  subjects.  The  tremendously  heavy  cost  of  subway 
construction,  which  already  lias  discouraged  or  postponed  progress  in  rapid  transit 
in  more  ihan  one  city,  will  lead  to  recognition  of  the  fact  that  subways  are  suited 
for  only  the  heaviest  traffic  requirements.  The  elevated  railway,  bridging  the  long 
gap  between  trolley-car  conditions  and  subway  conditions,  is  sure  to  receive 
increased  attention  in  the  future. 

EDITOR  ENGINEERING  XEWS. 


Contents 

Page 

HISTORY    AND    EXTENT  -      1 

ORGANIZATION  AND  PERSONNEL  OF  THE  ENGINEERING  STAFF  7 

GENERAL  ARRANGEMENTS  FOR  CONSTRUCTION — THE  OPERATING  CONTRACTS     14 

DESIGN  OF  STRUCTURE  AND  TRACK  -     21 

VENTILATION,    DRAINAGE    AND    WATERPROOFING — VENTILATION  27 

SEWERS,    PIPES    AND    CONDUITS — ELECTRIC    CONDUITS  -     30 

METHODS  OF  TIMBERING  TO  SUPPORT  THE  STREET  SURFACE  37 

E.\<  AVATION  -    41 

UNDERPINNING  BUILDINGS  ALONG  THE  LINE  47 

TUNNELS  IN  CITY  STREETS — THE  LEXINGTON  AVE.  TUNNELS  -     53 

THE  EIVER  TUNNELS — THE  HARLEM  RIVER  TUNNELS  58 

CONCRETE    WORK  -    63 
DESIGN   OF   STEEL   ELEVATED   RAILWAYS           ------        67 


Building  the  New  Rapid  Transit  System  of 

New  York  City 


History  airadl 


Extensions  to  the  existing  systems  of  rapid  transit  in 
the  City  of  Xew  York  have  been  planned  which  will  in- 
volve an  estimated  expenditure  of  $366,000,000.  The 
construction  of  these  lines  is  now  well  under  way  and  is 
being  rapidly  pushed  forward  at  a  rate  which,  it  is  hoped, 
will  insure  their  completion  by  the  end  of  the  year  1917. 
The  length  of  new  line  is  altogether  110  miles,  com- 
prising 325  miles  of  single  main-line  track.  These  addi- 
tions will  make  the  total  length  of  the  completed  sys- 
tem of  rapid-transit  railways  in  the  city  230  miles,  with 
621  miles  of  single  main-line  track.  The  mileage  of  main- 
line track  will  thus  be  approximately  doubled,  though  it 
is  expected  that  the  capacity  for  handling  passengers  will 
be  increased  threefold  or  fourfold. 

The  magnitude  of  this  work  may  be  at  least  partly  rea- 
lized by  comparison  of  its  cost  with  that  of  the  Panama 
Canal,  which,  including  the  $50,000,000  paid  to  the 
French,  is  to  cost  about  $375,000,000.  This  vast  enter- 
prise in  the  City  of  Xew  York  is  progressing  literally 
under  the  feet  of  its  five  million  inhabitants  and  the  other 
several  millions  of  the  adjacent  territory  whose  business 
brings  them  frequently  to  the  city,  with  hardly  any  no- 
tice or  disturbance  of  the  regular  routine  of  busi- 
ness. 

The  cost  is  to  be  borne  in  approximately  the  following 
proportions,  partly  by  the  city  and  partly  by  the  two  op- 
erating companies  which  will  divide  the  territory  between 
them  : 

City   of  New   York .  .  $200.000.000 

Interborough  Rapid  Transit  Co 105,000,000 

Xew   York   Municipal   Railway  Corporation 61,000,000 

The  first  of  these  two  operating  companies,  the  In- 
terborough  Eapid  Transit  Co.,  generally  spoken  of  as 
"The  Interborough,"  operates  the  present  subway  which 
traverses  the  length  of  Manhattan  Island,  reaching  into 
the  Borough  of  Bronx  at  one  end  and  a  short  distance 
into  Brooklyn  at  the  other.  It  also  operates  the  four  lines 
of  elevated  railway  in  Manhattan  and  the  Bronx,  as  well 
as  the  surface  lines  in  those  boroughs.  The  so-called 
Steinway  or  Belmont  Tunnel,  running  from  42nd  St., 
Xew  York,  under  the  East  Biver  to  Long  Island  City, 
was  built  about  five  years  ago  by  interests  closely  associ- 
ated with  the  Interborough  but  has  never  yet  been  uti- 
lized. It  is  now,  however,  to  be  finished,  equipped  and 
operated  by  that  company,  in  conjunction  with  the  other 
lines  of  its  system. 

The  Xew  York  Municipal  Railway  Corporation  is  a 
company  formed  by  the  Brooklyn  Rapid  Transit  Co.  to 
finance  and  operate  that  part  of  this  new  system  of  rail- 
ways which  falls  to  its  share.  The  Brooklyn  Rapid  Tran- 
sit Co.  is  familiarly  known  as  the  "B.  R.  T."  and  both  it 
and  the  Xew  York  Municipal  Railway  Corporation  will 
be  generally  so  referred  to  hereafter.  It  controls  all  the 
elevated  and  surface  lines  in  Brooklyn  including  those 
which  reach  the  famous  ocean  summer  resort  at  Coney 
Island. 

Heretofore,  the  operations  of  these  two  systems,  the  In- 


terborough and  B.  R.  T.,  have  been  almost  exclusively 
confined  to  territories  divided  by  the  East  River,  the  for- 
mer to  Manhattan  and  the  Bronx  on  its  west  side,  and  the 
latter  to  Brooklyn  and  the  Borough  of  Queens  on  the 
other  side. 

By  the  new  arrangement,  the  B.  R.  T.  gains  an  entrance 
into  Manhattan  by  a  new  tunnel  from  the  business  center 
of  Brooklyn  to  the  lower  end  of  Xew  York,  thence  via 
Broadway  and  7th  Ave.  through  the  center  of  the  busi- 
ness and  amusement  districts  to  59th  St.  Thence  it  turns 
eastward  and  crosses  the  East  River  on  the  Queensborough 
Bridge  to  a  connection  with  the  proposed  lines  to  Astoria 
and  Flushing.  It  also  reaches  lower  New  York  by  a 
series  of  underground  loops  connecting  the  three  lower 
East  River  bridges  and  the  new  tunnel  just  referred 
to,  which  will  permit  also  continuous  circulation  of 
its  trains  instead  of  bringing  them  in  as  at  present 
to  stub-end  terminals  at  the  New  York  ends  of  the 
bridges. 

The  Interborough,  besides  a  new  north  and  south  line 
in  Manhattan,  will  reach  the  Borough  of  Queens  and  will 
have  two  lines  to  Astoria  and  Flushing  from  42nd  St., 
via  the  Steinway  Tunnel.  Its  present  line  to  Brooklyn 


FIG.  1.  ROUTE  OF  AN  ELEVATED  RAILWAY  THROUGH  A 
CABBAGE  FARM  IN  QUEENS  BOROUGH 

is  to  be  extended  by  two  branches,  each  to  a  point 
some  five  or  six  miles  beyond  its  present  terminus 
at  Atlantic  Ave.  into  the  residential  section  of  that  bor- 
ough. 

The  Borough  of  Queens,  comprising  Long  Island  City, 
Astoria,  Jamaica,  Flushing,  etc.,  which,  up  to  the  present, 
has  never  been  served  by  any  so-called  Rapid  Transit 
Lines,  will  .now  have  the  two  elevated  lines  referred  to 
which  are  to  be  operated  jointly  by  the  two  companies, 
linked  up  to  both  the  Queensborough  Bridge,  the  Steinway 
Tunnel  and  the  2nd  Ave.  elevated,  and  thus  connect- 
ing directly  with  all  lines  in  Manhattan  and  other  bor- 
oughs. 

It  is  of  some  interest  perhaps  to  note  that  part  of 
this  route  in  Queens  through  Roosevelt  Ave.,  is  through 
a  street  not  yet  constructed  and  marked  on  the  ground 
only  by  monuments,  being  now  actually  used  for  market 
garden  purposes,  as  may  be  seen  by  the  accompanying 
photographs.  Figs.  1  and  2,  which  were  taken  looking 
along  the  center  line  of  the  street. 


[1] 


The  Borough,  of  Richmond  (Staten  Island)  is  event- 
ually to  be  connected1  with  the  B.  E.  T.  system  by  a 
tunnel  under  the  "Narrows,"  the  main  channel  connect- 
ing the  outer  bay  with  New  York  Harbor.  This,  how- 
ever, does  not  form  part  of  the  present  definitely  de- 
cided-on  scheme  of  construction. 

As  part  of  its  system  of  records  the  Commission  has 
had  many  hundreds  of  photographs  taken,  showing  in 
detail  the  character  of  the  streets  and  of  each  building 
adjacent  to  or  near  the  proposed  route  which  might  be 
expected  to  be  affected  in  any  way  by  the  construction. 
This  series  of  photographs  is  not  only  of  great  value 
for  reference  in  case  of  dispute  or  claim  for  damages, 
which  might  be  due  to  the  work  in  hand,  but  forms  a 
unique  and  interesting  historical  record  of  the  appear- 
ance of  the  city  at  this  time. 

EECEXT  HISTORY 

The  adoption  of  the  present  scheme  and  the  consum- 
mation of  the  contracts  under  which  the  work  is  now 
being  carried  out  is  the  result  of  negotiations  which 
have  been  carried  on  continuously  almost  ever  since  the 
completion  of  the  present  subway  in  1904. 

Almost  as  soon  as  operation  of  that  line  was  started 
it  was  seen  that  the  profits  from  operation  were  going 
to  be  much  greater  than  had  been  expected.  The  public 
lost  sight  of  the  fact  that  when  the  contracts  had  been 
first  proposed  it  was  with  considerable  difficulty  that 
anyone  had  been  induced  to  accept  them,  and  there  was 
a  great  outcry,  especially  by  the  sensational  newspapers, 
against  the  so-called  monopoly  of  the  Interborough,  and 
the  alleged  one-sided  bargain  with  the  city,  and  the 


<• 
FIG.  V.  A  STREET  IN  QUEENS  BOROUGH  OK  WHICH  AN 

RAILWAY  WILL  RUN 


demand  arose  that  any  future  subways  be  operated  as 
well  as  owned  by  the  city. 

Various  forms  of  contract  were  therefore  proposed,  but 
none  of  them  which  required  the  use  of  private  capital 
for  construction  was  acceptable  to  bidders  (see  ENG.  NEWS, 
Afar.  10,  1910,  p.  288  for  a  discussion  of  the  so-called 
Tri borough  route).  Finally  it  was  determined  to  start 
to  build  certain  sections  with  the  City's  money,  and  con- 
tracts were  let  for  the  construction  of  part  of  the  Fourth 
Ave.  subway  in  Brooklyn,  and  the  Centre  St.  loop  in  Man- 
hattan, but  no  arrangement  was  made  for  their  opera- 
tion, nor  was  any  made  until  the  final  agreement  arrived 
at  between  the  Public  Service  Commission,  the  City  and 
the  two  operating  Companies  on  Mar.  19,  1913. 

The  Public  Service  Commission,  which  succeeded  the 
old  Rapid  Transit  Commission,  was  appointed  and  took 
office  in  July,  1907.  A  new  city  administration  under 
Mayor  Gaynor,  and  including  among  its  members  Messrs. 
Mitchel-  (now  Mayor),  Prendergast  and  McAneny,  came 
into  office  Jan.  1,  1910. 

The  bids  for  the  Triborough  were  called  for  in  Octo- 


ber of  that  year.  As  noted  there  were  no  bids  for  con- 
struction by  private  capital,  but  numerous  bids  were 
received  for  construction  alone  with  city  funds.  The 
awards  for  this  latter  were,  however,  held  up  for  various 
reasons  in  spite  of  strenuous  protests  from  that  section 
of  the  press  and  public  which  allowed  the  large  profits 
of  the  Interborough  and  the  alleged  monopoly  of  this 
latter  to  obscure  their  judgment  as  to  the  best  interests 
of  the  city  and  the  traveling  public,  which  many  compet- 
ent authorities  considered  were  not  met  by  the  proposed 
scheme  for  the  Triborough  route. 

The  objections  to  the  Triborough  were  principally  be- 
cause it  was  proposed  to  build  the  lines  without  any  ar- 
rangement for  their  operation,  because  it  was  felt  that 
the  new  lines  should  be  linked  up  to  and  form  a  part 
of  the  present  system  (the  Triborough  as  laid  out  would 
not  have  permitted  transfer  except  on  payment  of  an 
extra  fare),  because  the  route  was  not  considered  well 
laid  out,  and  because  it  was  inadequate  to  meet  the 
growing  needs  of  the  city  and  to  properly  provide  for 
all  the  boroughs,  and,  above  all,  because  at  the  time  the 
amount  of  city  money  available  for  railway  construction 
was  very  limited  (not  more  than  60  to  70  million  dol- 
lars). 

From  the  beginning,  Mayor  Gaynor's  administration, 
through  the  Board  of  Estimate  (the  approval  of  which 
is  required  on  all  expenditures  of  the  city's  money) 
adopted  an  attitude  of  cooperation  with  the  Public 
Service  Commission,  and  the  present  contracts  are  the 
result  of  nearly  three  years  of  very  hard  work  and  the 
most  persistent,  patient  and  diplomatic  negotiation  be- 
tween these  bodies  and  the  companies  which  have  now 
finally  undertaken  the  operation.  It  was  necessary  that 
the  city's  credit  be  strengthened  and  its  borrowing 
capacity  be  enlarged,  and  this  in  itself  was  no  small 
part  of  the  task. 

During  all  this  period,  certain  sections  of  the  public 
press  were  very  bitter  in  urging  their  own  views,  and 
there  were  many  committees  of  citizens,  public  meetings, 
etc.  At  one  time  the  Interborough  entirely  withdrew 
and  everything  was  to  be  given  to  the  B.  R.  T.  The 
delay  was  well  nigh  intolerable  owing  to  the  congested 
and  crowded  condition  of  the  present  lines  of  transport ; 
but  it  is  felt  now  that  the  delay  has  been  more  than 
justified  by  the  comprehensiveness  of  the  scheme  evolved, 
the  consolidation  of  the  lines  into  two  large  systems, 
either  of  which  can  be  traversed  throughout  its  length 
for  a  single  fare,  and  the  conclusion  of  equitable  con- 
tracts by  which  not  only  will  the  city  own  the  lines  free  of 
cost  at  the  end  of  49  years,  but  will  have  shared  in  such 
profits  as  there  may  be  beyond  a  certain  stated  amount. 

It  may  not  be  out  of  place  to  emphasize  the  advantage 
to  the  city  from  the  perpetuation  of  the  virtual  monopoly 
of  these  two  companies  under  fair  and  efficient  regula- 
tion. The  public  is  not  only  allowed  a  ride  for  a  single 
five-cent  fare  over  the  lines  of  a  complete  system  reach- 
ing almost  to  every  part  of  the  City  of  Greater  New 
York,  but  the  city  shares  in  such  profits  as  there  may  be 
from  the  consolidation  of  the  management  and  its  own 
contribution  of  credit  in  obtaining  the  greater  part  of 
the  money  at  low  rates  of  interest.  A  most  important  con- 
sideration is  also  that  which  provides  complete  plans  in 
detail  of  the  operation  of  all  routes  in  advance  of  design 
and  construction,  so  that  these  latter  can  proceed  with  an 
intelligent  conception  of  the  operating  requirements. 


[2] 


CHARACTER  OF  THE  LINES 

The  325  miles  of  new  lines  already  decided  on  will 
be  built  underground  in  the  more  thickly  populated  sec- 
tions of  Manhattan  and  Brooklyn  and  elevated  in  the 
outlying  districts.  The  subway  will  embrace  various 
types  of  structures,  both  for  two,  three  and  four  tracks, 
the  latter  in  some  cases  all  at  the  same  level ;  in  others 
as  a  double-deck  structure,  each  level  having  two  tracks. 
There  are  to  be  several  tunnels  under  the  rivers,  some 
sunk  from  the  surface  by  methods  similar  to  those  de- 
veloped at  the  Detroit  tunnel,  and  others  probably  to 
be  driven  by  the  shield  method.  The  elevated  will 
be  mostly  a  steel  structure  of  the  familiar  type,  though 
of  modern  construction,  but  in  some  cases  where  park- 
ways or  boulevards  are  crossed  or  traversed  it  is  being 
built  of  reinforced  concrete  with  special  attention  to 
artistic  architectural  design,  as  illustrated  in  Fig.  3. 

IMPROVEMENTS  IN  DESIGN 

On  all  the  new  lines  a  special  effort  will  be  made  to 
locate  all  the  stations  on  tangents  so  as  to  avoid  the  in- 


trains  stir  up  the  air  in  passing,  they  do  not  change  it 
very  much,  and  not  nearly  to  the  extent  so  noticeable  in 
all  the  single-track  tube  tunnels  already  built  under  the 
waters  of  Xew  York  Harbor  and  on  all  the  lines  of  the 
Hudson  &  Manhattan  Co. 

Another  point  of  interest  is  the  provision  of  or  for 
three  tracks  on  the  lines  in  the  outlying  districts  where 
the  density  of  travel  does  not  require  four  tracks  for 
continuous  express  service.  This  allows  express  service 
one  way  during  the  rush  hours. 

EXISTING  LINES 

The  principal  features  of  the  rapid  transit  lines  now 
in  operation  in  Manhattan  are  the  four  elevated  lines 
running  north  and  south  through  Second,  Third,  Sixth 
and  Ninth  Aves.,  the  principal  parts  of  which  were  built 
between  18TO  and  1880,  and  the  present  subway,  built 
between  1900  and  1904.*  In  Brooklyn  the  existing  ele- 
vated lines,  which  were  built  soon  after  those  in  Man- 
hattan, radiate  from  the  old  Brooklyn  Bridge,  one  group 
westerly  toward  Jamaica  and  the  other  toward  Coney 


ENG.NEWS 


FIG.  3.  DESIGN  FOK  ORNAMENTAL  REINFORCED-CONCKETE  VIADUCT  ox  QUEENS  BOULEVARD 


convenience  and  possibility  of  danger  from  the  space 
between  the  car  and  the  platform  on  curves,  which  oc- 
curs at  some  places  on  the  existing  subway  lines.  An 
endeavor  lias  also  been  made  in  so  designing  the  structure 
at  the  junctions  and  connections  of  main  lines  and 
branches,  etc.,  to  avoid  grade  crossings  of  the  various 
tracks.  With  the  abnormal  density  of  traffic  during  the 
rush  hours  this  is  very  desirable,  as  the  slightest  delay 
at  any  one  point  may  be,  and  generally  is,  reflected  over 
the  whole  system.  Footpaths  at  the  sides  of  the  tunnels 
at  the  level  of  the  car  platforms,  similar  to  those  built 
in  the  Pennsylvania  R.R.'s  Xew  York  tunnels,  are  to  be 
constructed  so  as  to  provide  a  walk  for  passengers  in 
case  a  train  should  meet  with  an  accident  and  be  stalled. 

The  new  subway  will  be  divided  by  partitions  so  as  to 
separate  the  trains  going  in  different  directions,  with  the 
expectation  of  thereby  so  improving  the  ventilation  by 
utilizing  the  piston-like  action  of  the  trains  to  change 
the  air  that  the  accumulation  of  excessive  'heat  so  no- 
ticeable in  the  summer  in  the  present  subway  mav  be 
avoided. 

In  furtherance  of  this  also,  waterproofing  will  be 
omitted  when  it  is  possible  to  do  so,  as  it  is  thought  that 
the  practical  inclosure  of  the  existing  subway  in  a  wa- 
terproof envelope  materially  helps  to  prevent  the  diffusion 
of  the  generated  heat  through  the  walls  of  the  struc- 
ture. As  is  well  known,  locally  at  least,  this  accumu- 
lation of  heat  in  the  subway  in  the  summer  time,  due 
to  the  heating  of  the  motors,  the  friction  of  brakeshoes 
on  wheels,  the  wheels  on  the  tracks,  etc.,  has  made  trav- 
eling very  uncomfortable  at  times,  the  installation  of  ex- 
pensive ventilating  apparatus  having  only  partially  al- 
leviated the  trouble.  In  the  present  subway  there  are 
no  division  walls  between  the  tracks,  and  while  the 


Island.  Some  of  these  last-mentioned  lines,  after  reach- 
ing a  point  some  five  or  six  miles  from  the  bridge,  drop 
to  the  surface  and  remain  there  for  the  rest  of  the  way 
to  Coney  Island,  and  all  these  are  to  be  elevated  (or 
depressed  in  open  cuttings),  and  are  shown  on  the  map 
as  new  elevated  lines  of  the  B.  R.  T.,  although  through 
trains  from  the  bridge  to  Coney  Island  are  operated 
over  them  now. 


TRAFFIC 


Almost  ever  since  the  elevated  lines  were  first  put  into 
operation,  it  has  been  notorious  that  the  congestion  and 
crowding  of  the  transportation  lines  of  New  York  have 
been  unequaled  on  any  other  transportation  system  in 
the  world.  The  opening  of  the  present  subway  in  1904, 
although  it  had  then  a  capacity  of  400,000  passengers 
per  day,  afforded  little  relief.  By  the  lengthening  of 
the  express  platforms  to  accommodate  10  instead  of 
eight  cars,  the  installation  of  the  most  modern  and  ap- 
proved types  of  automatic  block  signals,  brakes,  car 
and  air-line  couplings,  center  side  doors,  etc.,  its  ca- 
pacity was  increased  so  that  1,250,000  passengers  can 
be  and  have  been  handled  in  24  hours,  but  the  crowding 
during  the  rush  hours  is  as  bad  as  ever  on  all  lines. 

The  following  figures,  condensed  from  a  table  given 
in  the  last  report  of  the  Public  Service  Commission,  with 
the  addition  of  the  figures  for  1913,  show  the  great  and 
greatly  increasing  amount  of  travel,  and  justify  the 


*A  history  of  the  rapid  transit  situation  up  to  that  date 
and  a  full  description  of  the  construction  features  of  the 
original  subway  were  published  in  a  series  of  articles  in  "En- 
gineering News,"  Vol.  XLVII,  Jan.  to  June,  1902,  while  a  de- 
scription of  the  proposed  Triborough  Route  and  further 
notes  to  date  will  be  found  in  the  "Engineering  News"  of 
March  10,  1910,  p.  288. 


[3] 


EN6.NEWS 


Total 

735 

993 

1342 

1659 


FIG.  4.  THE  OLDER  NEW  YORK  RAPID  TRANSIT  SYSTEM 

AND  THE  NEW  LINES  Now  UNDER  CONSTRUCTION 

AND  PIA.NNED 

attempt   to  meet  the  requirements  by  the  system   now 
proposed,  enormous  though  'tis  cost  will  be: 

NUMBER    OP    PARES    COLLECTED    (MILLIONS) 
Manhattan  and 

Bronx  Brooklyn  Queens 

Subway      Elev.        Surface    All  lines  Surface 
1898..  184  321  221  9 

1903 246  427  304  16 

1908 200  202  411  419  30 

1913 327  307  494  484  47 

(Note — In  1905,  its  first  year  of  operation,  the  Subway 
carried  75,000,000  passengers.  In  1914  it  carried  340,400,000 
passengers.) 

Ever  since  the  opening  of  the  present  subway  in  1904, 
plans  for  extensions  have  been  under  consideration,  first 
by  the  old  Rapid  Transit  Commission  and  since  then  by 
its  successor,  the  Public  Service  Commission  for  the 
First  District  of  New  York,  but  for  the  reasons  already 
given  there  were  various  delays  until  the  present  com- 
prehensive scheme  of  routes  was  developed  to  give  so 
far  as  possible  and,  as  may  be  seen  by  the  maps,  fair 
and  equitable  service  to  all  parts  of  the  greater  city. 


FIG.  5.  SUBWAY  LINES  AND  ELKVATED  LINKS  IN  THE 
COMPLETED  RAPID  TRANSIT  SYSTEM 

There  had  been  for  some  time  a  feeling  that  Manhattan 
had  been  unduly  favored  at  the  expense  of  the  other 
boroughs,  and  while  this  to  some  extent  is  reasonable, 
both  that  it  had,  and  that  it  should  be,  there  can  be 
little  fault  found  with  the  scheme  now  laid  out. 

The  routes  of  the  various  extensions  and  their  charac- 
ter are  shown  on  the  maps,  Figs.  4,  5  and  6,  but  for  the 
benefit  of  those  not  entirely  familiar  with  the  situation 
it  may  be  well  to  briefly  enumerate  their  salient  features 
and  some  of  the  details  of  the  scheme. 

NEW  LINES 

THE  INTERBOROUGH — Tn  Manhattan  the  Second,  Third 
and  Ninth  elevated  lines  will  complete  the  installa- 
tion of  third  tracks  from  the  down-town  business  sec- 
tion to  above  125th  St.,  thus  enabling  express  trains  to 
be  run  down-town  in  the  morning  and  up-town  at  night. 

The  present  subway  will  be  divided  at  42d  St.,  the 


[4] 


FIG.  6.  THE  SYSTEMS  OF  THE  Two  OPERATIXG  COM- 

PAXIES,  THE  IXTERBOKOUGH  AXD  THE  BROOKLYX 

RAPID  TRAXMT 

lower  part  being  connected  with  the  new  Lexington 
Ave.  subway,  giving  a  four-track  line  all  the  way  xtp  the 
East  Side,  splitting  into  two  three-track  branches  in  the 
Bronx  after  it  crosses  under  the  Harlem  Eiver:  tin- 
upper  part  will  be  connected  to  the  new  Seventh  A\v.- 
Varick  St.  line,  thus  giving  a  through  route  up  and 
down  the  West  Side,  and  placing  the  Pennsylvania  Ter- 
minal at  33d  St.  on  a  main  line  of  the  Rapid  Transit 
system.  The  present  West  Farms  branch  of  this  line 
in  the  Bronx  will  be  extended  some  five  miles  farther  to 
the  Mount  Yernon  line  at  the  northerly  boundary  of 
the  city. 

The  Brooklyn  end  of  the  present  subway  will  be  ex- 
tended from  Atlantic  Ave.  by  two  branches  via  Flat- 
bush  Ave.  and  Eastern  Parkway  into  the  residential  sec- 
tions of  Brooklyn. 

The  part  of  the  present  subway  on  42d  St.  between 
the  Grand  Central  Station  and  Times  Square  will  be 


operated  by  a  shuttle  service  between  the  main  lines  on 
the  East  and  West  Sides. 

The  Steinway  tunnel  will  be  extended  back  to  Times 
Square  and  forward  to  the  east  end  of  the  Queensbor- 
ough  Bridge,  where  it  will  connect  with  the  two  lines 
to  Astoria  and  Flushing,  over  which  both  systems  are 
to  have  trackage  rights.  The  Second  Ave.  elevated  will 
be  connected  to  the  Queensborough  Bridge  and  so  to 
these  same  two  lines. 

There  will  be  certain  other  small  extensions  and  con- 
nections to  allow  the  proper  linking  up  of  the  various 
lines  and  permit  desirable  or  convenient  combinations 
in  the  operation  of  trains,  all  of  which  are  shown  on 
the  maps. 

The  Interborough  will  thus  have,  besides  its  four  ele- 
vated lines,  four  double-  or  three-track  branches  in  the 
Bronx  leading  to  two  main  trunk  lines  (four-track) 
throughout  the  length  of  Manhattan  on  Fourth  and 
Seventh  Aves.  to  two  tunnel  routes  under  the  East  River, 
joining  under  Fulton  St.,  the  main  business  street  of 
Brooklyn,  and  then  spreading  out  again  into  two 
branches  into  the  residential  section  of  that  borough. 
The  distance  from  the  upper  end  of  the  Bronx  to  the 
ends  of  the  lines  in  Brooklyn  is  about  26  mlies.  From 
the  center  of  this  system  there  will  be  the  offshoot  at 
42nd  St.  via  the  Steinway  tunnels  to  the  lines  in  the  Bor- 
ough of  Queens  to  Astoria  and  Flushing. 

THE  BROOKLYX  RAPID  TRAXSIT — Besides  certain  ex- 
tensions of  various  lines  in  Brooklyn  and  the  con- 
struction of  the  elevated  structures  in  South  Brook- 
lyn on  the  Coney  Island  lines,  as  already  referred  to, 
the  main  features  of  the  contract  of  this  company 
with  the  city  are  those  which  provide  for  its  en- 
trance into  New  York  and  the  linking  up  of  the  four 
bridges  across  the  East  River  into  lines  of  through  travel 
instead  of  establishing  terminals  at  their  ends.  There 
is  one  important  new  line  in  Brooklyn,  the  Fourth  Ave. 
subway,  which  was  started  some  five  years  ago,  a  con- 
siderable part  of  which  is  now  nearly  •  completed ;  this 
route  extends  from  the  Manhattan  Bridge  through  Fourth 
Ave.  to  Fort  Hamilton,  and  will  be  part  of  an  important 
new  route  to  Coney  Island. 

The  principal  line  of  the  B.  R.  T.  in  Xew  York  will 
be  that  already  described,  running  from  the  center  of 
Brooklyn  under  the  East  River  and  via  Broadway  and 
Seventh  Ave.  to  59th  St.,  the  Queeusborough  Bridge 
and  to  Astoria  and  Flushing.  This  will  be  a  four-track 
line  in  Manhattan  above  City  Hall  (Park  Place). 

From  a  certain  point  of  view,  the  linking  up  of  the 
Xew  York  end  of  the  three  down-town  East  River 
bridges,  the  old  Brooklyn  Bridge,  the  Manhattan  just 
above  it,  and  the  Williamsburg  Bridge,  a  mile  farther  up 
the  river,  is  one  of  the  most  interesting  features  of  the 
whole  scheme.  For  years  the  crowding  and  congestion  at 
the  ends  of  the  Brooklyn  Bridge  were  worse  than  even  on 
the  elevated  and  subway  lines.  Xearly  all  the  travel  from 
the  lines  of  the  B.  R.  T.  was  concentrated  at  this  one 
bridge  and  brought  over  to  a  stub-end  terminal  at  the 
Xew  York  end.  In  an  attempt  to  provide  better  means 
of  communication  between  Brooklyn  and  New  York,  the 
Williamsburg  Bridge  was  built  and  opened  in  1905  and 
the  Manhattan  Bridge  in  1908.  No  provision  was  made, 
however,  for  the  operation  of  these  bridges  or  their 


[5] 


proper  connection  with  any  of  the  existing  lines  of  com- 
munication, and  the  people  from  Brooklyn  have  been 
brought  over  to  the  New  York  ends  and  dumped  there, 
to  make  the  best  of  their  way  to  their  destination.  The 
travel  between  Brooklyn  and  Xew  York  is  nearly  al! 
toward  New  York  in  the  morning  and  toward  Brook- 
lyn at  night,  all  four  of  the  East  River  bridges  pro- 
viding for  lines  of  rapid  transit  (two  or  four  tracks) 
as  well  as  for  street  cars,  ordinary  vehicular  traffic  and 
pedestrians. 

To  eliminate  the  stub-end  terminals  the  so-called 
Centre  St.  loop  was  planned  to  connect  up  the  New 
York  ends  of  these  three  bridges,  and  its  construction 
was  started  in  1907,  though  no  arrangement  was  made 
for  its  use.  Now,  however,  it  is  to  be  completed  to  a 
connection  with  the  new  tunnel  which  is  to  connect  the 
B.  R.  T.  with  its  Broadway  line.  This  will  enable 
all  the  trains  to  circulate,  coming  over  on  one  bridge, 
continuing  and  returning  via  another  instead  of  coming 
into  a  terminal  in  the  congested  district  and  having  to 
back  out. 

There  will  be  also  another  new  route  established  un- 
der 14th  St.,  New  York,  and  the  East  River,  to  the 
easterly  section  of  Brooklyn  (East  New  York). 

FARES 

The  contracts  between  the  city  and  the  two  operating 
companies  provide  for  a  single  fare  of  five  cents  on 
each  system,  with  free  transfers  at  intersecting  points 
for  a  continuous  ride  in  the  same  general  direction.  On 
the  Brooklyn  system,  transfers  will  be  exchanged  be- 
tween the  elevated  lines  and  the  subway  lines,  but  on  the 
Interborough  only  such  transfers  as  are  now  given  will 
be  provided  between  the  elevated  railroads  and  the  sub- 
way. On  the  existing  lines,  as  they  stand  today,  the 
longest  ride  obtainable  for  five  cents  is  through  the  sub- 
way from  Atlantic  Ave.,  Brooklyn,  to  Van  Cortlandt 
Park  or  242nd  St.  on  the  Broadway  branch,  a  distance 
of  17^  niiles.  Under  the  dual  system,  as  the  new  sys- 
tem has  been  commonly  called,  it  will  be  possible  to 
travel  over  the  Interborough  subway  from  the  terminus 
of  the  White  Plains  Road  line,  near  the  northern  city 
boundary,  the  whole  length  of  the  Bronx  and  Manhat- 
tan, under  the  East  River  to  Brooklyn,  and  through  the 
Eastern  Parkway  subway  and  its  extensions  to  New  Lots 
Ave. — a  distance  of  about  26  miles — for  one  fare  and 
without  change  of  cars. 


The  longest  ride  on  the  Brooklyn  system  will  be  from 
Flushing,  at  the  end  of  the  Corona  branch,  to  and  across 
the  Queensborough  Bridge,  through  the  Broadway  sub- 
way in  Manhattan,  under  the  East  River  to  Brooklyn 
and  through  the  Fourth  Ave.  subway  and  its  connections 
to  Coney  Island,  about  2 1  miles,  for  five  cents. 

The  fare  from  the  center  of  Brooklyn  to  Coney  Island 
had  always  been  10  cents  (15  cents  from  New  York) 
up  to  within  the  last  few  years,  when  a  general  agita- 
tion for  its  reduction  was  started. 

As  soon  as  the  connections  of  the  Fourth  Ave.  subway 
in  Brooklyn  with  the  elevated  lines  are  made  and 
through-train  operation  is  possible  from  Manhattan  to 
Coney  Island,  the  five-cent  fare  between  these  points 
will  apply.  This,  it  is  estimated,  will  take  about  18 
months. 

CHANGES  IN  METHODS  OF  COMMUNICATION  IN  XEW 
YORK 

Before  leaving  the  general  subject  of  routes,  it  may 
not  be  amiss  to  call  attention  to  the  radical  change  in 
the  character  of  the  means  of  communication  between 
New  York  City  proper  (Manhattan)  and  the  surround- 
ing territory,  which  has  taken  place  in  the  last  six  or 
eight  years.  Direct  land  communication  has  never  been 
possible  except  to  the  north,  while  the  most  densely  pop- 
ulated of  the  surrounding  districts  have  been  to  the  east 
in  Brooklyn  and  the  west  in  New  Jersey,  with  which 
communication  was  only  possible  by  means  of  boats  of 
one  kind  or  another,  and  from  both  of  which  districts 
enormous  numbers  of  people  come  to  Manhattan  daily. 

Brooklyn  was  connected  with  Manhattan  by  means  of 
the  famous  Brooklyn  Bridge  as  long  ago  as  1883 :  but 
with  the  completion  of  that  structure  progress  along 
these  lines  stopped  for  almost  a  quarter  of  a  century. 
Within  the  last  eight  years,  however,  three  more  bridges 
have  spanned  the  East  River  and  six  pairs  of  railway 
tunnels  have  been  put  into  service  under  the  rivers,  one 
pair  more  has  been  built,  three  pairs  are  to  be  built 
under  the  present  scheme,  making  four  bridges  and  ten 
pairs  of  tunnels  for  railways,  besides  which  there  haw 
been  built  two  tunnels  for  gas  and  one  for  water-supply, 
and  thus  making  practical  the  direct  physical  connection 
of  Manhattan  by  land  lines  of  communication  with  the 
populous  districts  to  the  east  and  wot. 


LCI 


Few  j>cople,  even  in  Xew  York  City,  realize  the  gigan- 
tic task  of  constructing  230  miles  of  rapid-transit  lines 
into  and  through  the  heart  of  the  most  congested  districts 
of  Xew  York  City — a  system  of  elevated  and  under- 
ground electric  railways  of  far  greater  mileage  and  more 
complete  in  every  respect  than  any  similar  system  in  the 
world.  This  work  is  being  carried  on  under  the  direction 
of  the  Public  Service  Commission  of  the  First  District  of 
the  State  of  New  York,  which  besides  having  direct  charge 
of  the  construction  of  these  new  rapid  transit  lines  also 
supervises  the  operation  of  all  public  utilities  companies, 
inspects  and  passes  upon  equipment,  services  and  rates  of 
.ill  existing  transportation  lines,  whether  surface,  rapid 
transit,  interurban  or  regular  steam  railroads,  etc..  as 
\\ell  as  gas,  electric  light,  power  and  telephone  companies. 

ORGANIZATION 

The  chart,  p.  8.  shows  graphically  the  organization 
of  the  engineering  staff  engaged  in  subway  and  rapid- 
transit  design  and  construction  and  incidental  work.  Xot 
shown  on  the  chart  is  an  Electrical  Engineer,  the  head 
of  a  separate  bureau  of  some  60  engineering  employees, 
a  bureau  of  gas  and  electricity,  and  a  transportation  bu- 
reau, each  employing  several  engineering  inspectors.  The 
titles  of  the  various  employees  and  the  salaries  of  each 
grade  are  shown  in  a  table  accompanying  the  chart. 

Complex  as  the  organization  appears,  it  is  founded  on 
strictly  military  principles.  There  are  two  grand  di- 
visions, nmghly  the  groups,  on  the  right  and  left  respec- 
tively: (1)  the  actual  supervision  of  construction,  under 
l.'.iU-rt  liidgway.  Engineer  of  Subway  Construction  :  ( v!  i 
the  administrative  and  executive  work,  design,  subsur- 
face -tructures.  estimates,  etc.,  under  Daniel  Lawrence 
Turner.  Deputy  Engineer  of  Subway  Construction. 
Through  these  lieutenants  all  the  various  subordinates 
report,  except  the  Electrical  Engineer,  who  reports  di- 
rectly to  the  Chief  Engineer.  To  each  subordinate  is 
designated  his  explicit  authority  and  responsibility,  to 
which  he  is  held  strictly  accountable. 

EFFICIENCY  BECORDS — To  foster  enthusiasm  and  as- 
sure promotion  to  the  deserving,  a  quarterly  record  is 
kept  of  each  employee's  ability  rating  and  effici- 
ency rating  as  determined  by  his  immediate  superior. 
Each  rating  has  an  established  value  which  is  added  to 
or  subtracted  from  the  employee's  efficiency  percentage. 
The  system  is  quite  elaborate,  but  has  been  in  service  for 
more  than  four  years  and  is  giving  eminent  satisfaction. 
It  is  the  aim  of  the  Chief  Engineer  to  fill  all  the  respon- 
sible positions  by  promotion,  and  whenever  a  vacancy  oc- 
curs, promotion  examinations  are  held,  which  are  open 
only  to  those  who  have  served  in  lower  positions  for  a 
predetermined  period  of  time  and  have  maintained  an 
efficiency  record  of  at  least  60%,  for  a  given  period. 

PROMOTION-  EXAMINATIONS — An  example  of  such  an 
examination  was  one  held  a  year  ago  for  the  position  of 
Assistant  Division  Engineer.  This  was  open  only  to  A  — 


•Although  this  article  was  prepared  by  the  editors  of  "En- 
gineering News,"  it  la  made  a  part  of  this  series  of  articles 
on  the  construction  of  the  new  subway  and  elevated  lines  in 
New  York  City,  in  order  that  the  presentation  may  be  com- 
plete as  a  whole. 


sistant  Engineers  and  Designers  of  Grade  10.  The  sub- 
jects of  the  examination  and  the  relative  weights  were: 
(a)  A  paper  on  some  subject  relevant  to  the  work  of  the 
applicant,  weight  1;  (b)  efficiency,  weight  3.  The  paper 
was  to  be  typewritten  and  illustrated  with  drawings  or 
photographs,  and  accompanied  by  an  affidavit  to  the  effect 
that  it  was  an  original  composition  of  the  applicant.  The 
practicability  of  such  a  test  is  readily  appreciated  and 
illustrates  how  an  enthusiastic,  loyal  and  efficient  staff 
may  be  built  up  and  maintained,  while  still  keeping 
strictly  both  to  the  letter  and  the  spirit  of  the  civil-ser- 
vice laws. 

DUTIES  OF  EACH  BANK — The  specific  duties  of  the 
members  of  each  rank  (in  the  subordinate  positions  there 
are  several  grades  in  each  rank  according  to  salary)  are 
given  below: 

CHIEF  ENGINEER — In  general  charge  over  all  work 
under  the  Engineering  Department,  including  the  preparation 
of  plans  for  and  the  construction  of  subway  and  elevated 
work  by  the  City,  and  the  approval  of  plans  for  and 
supervision  over  the  construction  and  equipment  of  subway 
and  elevated  lines  by  the  operating  companies  under  the  Dual 
Contracts,  aggiegating  a  total  cost  of  nearly  $350,000,000. 

ENGINEER  OP  SUBWAY  CONSTRUCTION— Deputy  hav- 
ing general  supervision  in  the  fleld  over  the  construction  of 
all  subway  and  elevated  work  prosecuted  by  the  City  or  com- 
panies, including  general  supervision  over  the  five  fleld  di- 
visions and  the  Divisions  of  Sewers  and  Inspection  of  Ma- 
terial. Acts  as  Chief  Engineer  in  the  absence  of  Chief  Engi- 
neer. 

DEPUTY  ENGINEER  OF  SUBWAY  CONSTRUCTION  — 
Deputy  having  general  supervision  over  all  administrative 
and  organization  work,  including  general  supervision  over 
the  general  office  and  Divisions  of  Designs,  Subsurface 
Structures,  Track  Work  and  Estimates,  and  the  Electrical 
Engineering  Division  with  respect  to  new  subway  work. 
Acts  as  Chief  Engineer  in  the  absence  of  the  Chief  Engineer 
and  the  Engineer  of  Subway  Construction. 

PRINCIPAL  ASSISTANT  ENGINEER — In  charge  of  the 
Division  of  Designs.  In  direct  charge  of  the  designing  of  all 
subway  and  elevated  work  and  preparing  contract  and  de- 
tailed plans  with  respect  thereto,  and  also  examines  and 
passes  upon  construction  plans  for  work  prosecuted  by  the 
operating  companies. 


I  SHU  ON  ORGANIZATION  CHART  ON 
THE  XEXT  PAGE 

Title  Salary 

Chief    Engineer     $20,000 

Engineer  of  Subway  Construction          12,000 

Deputy    Engineer    8,000 

Principal    Assistant    Engineer 7,000 

Division    Engineer     7,000 

Electrical   Engineer    6,000 

General  Inspector  of  Materials....  4,500 
Assistant  Inspector  of  Materials...  2,400 
Engineer  Sub-Surface  Structures..  4,500 

Designing  Engineer    3,750 

Designing    Architect     4.200 

Sr.  Assistant  Division  Engineer.  . .  4,200 
Sr.  Assistant  Designing  Engineer.  .  4,200 
Sr.  Assistant  Designing  Architect.  3,750 

Assistant    Division    Engineer    3.750 

Assistant   Designing   Engineer    ....          3.750 

Assistant    Engineer    1801-2700 

Designer    1801  -2400 

Architectural    Designer     1801-2400 

Jr.    Engineer    1201-1800 

Draftsman    1201-1800 

Architectural    Draftsman     1201-1800 

Jr.    Assistant    901-1200 

Chemist    901-2700 

Inspector    901-2700 

Tester     .  901-2700 


Abbreviation 

C.  E 

E.  Sub.  Con 

Dep.  E 

P.  A.  E 

D.  E 

Elec.  E 

G.  I.  M 

A.  I.  M 

E.  Sub.  Surf.  Str. 

Des.  E 

Des.  Ar 

S.  A.  D.  E 

S.  A.  Des.  E 

S.  A.  Des.  Ar.  .  .  . 

A.  D.  E 

A.  Des.  E 

A.  E 

Des 

Ar.  Des 

J.  E 

Df 

Ar.  Df 

J.  A 

Che 

T. 

T. .  . 


^ 


DF 


DtS, 


JA: 


~DT 


SE 


fit 

J.A. 


SEWER      DIVISION 


MATERIAL    INSPECTION    DIVISION) 


"I 

CT.T. 

II.CD.I      (fH 

n 

I.SL 

Cl.l 

ll.CD.I        let 

3 

I.SL. 

Cl.l. 

I.SL. 

Cl.l 

I.SL 

CV1. 

I.SL. 

CT.T. 

I.SL 

CT.T. 

I.bl. 

l.bL. 

l.SI 

I.SL 

I.SL. 

l,bL 

SUB-5URF.-STRUCTURE5  DIVISION 


I 

A.E. 

AE 

AE. 

J.t. 

J 

t. 

j 

t. 

J.A. 

J.t. 

J 

t. 

j 

t. 

J.A. 

J.A. 

JA. 

JA. 

JA 

JA. 

JA. 

J.A. 

J.A. 

J 

A. 

JA 

JA. 

J.A. 

JA 

J 

A 

J.A. 

JA 

J.A. 

JA. 

JA. 

J.A 

J 

A. 

n 

DF. 

A.E. 

L>k 

J.t. 

J.E. 

JAOT 

J.Ct 

J.A. 

FIRST       DIVISION 


JJL  JJL 


JA. 


JA  JA 

J.A.  J.A 

JT  IE 


JA 
JA. 


J.E,"  J,E. 


J.A 


JA 

JA, 
J.A 


JA. 


J.A 


AE. 

At' 
J.t. 
J.A. 


JA 

jXA 


SECOND      DIVISION 


AE. 

AE 

A.E. 

A.E. 

.AJE. 
J.F 

J:ET 

J  F 

AE. 

J.E. 

J.t 

J.F. 

J.E. 
J.E. 

J.E. 

JF 

Ji 
J.A. 

J  F 

JJL 
JA 
JA 
J.A 
JT 

J.F 

JA. 

J.A. 
J.A. 

JA 

JA 

JA, 

JA. 

JT 

JA 

JA. 

J.A 

JA. 

J.A 

JA. 

J.A. 
J.E. 

JA. 
J.E. 

J.A. 

XT 

J.A 

J.E. 

J.E. 

J.A. 

J.A 

JA. 

JA: 

JA. 

J.A, 

JA: 

JA 

J.A 
J.A 

JA. 

J.A. 

J.A. 
JA 

J.A 

J.A. 

J  A 

JA. 

JA 

JA 


,  J.E. 
JA.  JA. 
JA  JA. 

HIT 

JA  JA 
JA.  J.A 
JAiJJA 


JJL 
JA 
JA 

JT 

JA 


J.A. 


AE_, 

J.E. 


JA 


AF 


J.F 


JF 


JA. 


JA 


J.A 


J.E. 


J  A. 


J.A 


J.A. 


J.A 


JA 
J.A 


A.E. 


JA 


J.A, 


JA  JA 

JAJLJA 


,u 


JJL 

-rJ'E- 
JA.   J.A, 


JA   J.A 
JA    JA. 

33  SA 


THI  RD          DIVISION! 


-A.E 

JJLlpi 
7F 

JA" 


J.A 


J  A 


JA 


JJL  JJL  JJL 


JA 


JA,   JA 


JA. 


A.E 
JJL 

J.E 


JA  JA 


J.A. 


JA 


AE 

JJL 
J'E. 

JA 

JA], 

J.A.  [JA. 

JJL  iL 


JA 


A.E. 


J.E 


J_[ 


JA 


J.A, 


J.A. 


J.E. 


JA 


J.A 


JA 


JJL 
\TT 
JA 

JA 

J.A, 


JA 


fJT  jTl 


JT 

J.A. 
JX 

JA 


S  I  XT  H       D1V  I  S1ON 


JA. 


JA 
J.A 
J.A. 


J.E 
J.A 

jX] 

JAJUA 
J.E 


J.A 

JA] 


J.E;. 
J.E 
J.A. 

J.A 


J.A 
JA 
JA] 


AL 

JJL 
J,L 
JA 
JX 


JA. 


A.E. 

J.E 
J.E 
JA 


J.A 
J.A. 

[JA 


AJL 

J.E. 
J.E. 
JA. 
JA 


J  A 


A.E. 

JE 
J.E 


JA. 


Ai 

JE. 

JJL 


JA 
J.E 


AE 

EL 

JJL 

JA 

J.A, 

it 

JA 

AF 

jf 

JJL 

JA 

A.E. 

;rr 

A.E. 

JJL 
Ji 

JA. 

AE 

A.E 

J.E. 
J.F. 

A.E. 

A.E. 

J.E 

AE. 

A.E. 

s* 

Ji 
JJL 

J  A 

JJL 
J  F. 

J  F 

J.E. 
J.E. 

J.fc 
J.E. 
JA 

JA. 

^ 

Ji 

JA 

J.E. 

JJL 

JA 

J.E. 
J.A. 

J.A. 

JA. 

JA_ 
J.A 

,1  A, 

JA 

J  A 

JA, 

JA. 

JA. 

J.A 

J.A: 
IT 

JA 

J.A. 

J.A. 
JA. 
JT 

JA 

IE 

JA 

ft 

J  A 

J^ 
JA 

IJA. 
jr 

JA 

J.A. 

JT 

J.A. 

JT 

J.A. 

JT 

J.E. 

J.A. 

J.A 

J.A. 

JA 

JA 

JA. 

J.A. 

JA 

J  ft 

.1  A. 

JA. 

J 
LI 
31V 

A 
_A_ 

ISI 

J.A. 

JA. 
JA. 

J  A. 

JA 

JA. 

J.A 

J.A. 

J  A 

LuJ 
a•lo^ 

LvJ 

1  FIN 

LJAJ 

5H 

J.A. 

J.A. 

LLAJ! 

IJ.A.IIJ.A.I 

ST> 

ON 

j 

.F. 

A 

E. 

A.t 

.E. 

J 

E. 

J.E 

- 

.h. 

J 

E. 

J.t 

. 

.E. 

J. 

L. 

J 

h 

J 

.E. 

J 

E 

J 

E 

ORGANIZATION  CHART  OF  THE  ENGINEERING  STAFF  OF  THK  PUBLIC  SKI.-VICI-:  COMMISSION 

[8] 


DIVISION  ENGINEER — In  direct  charge  of  a  division  of 
construction  work  in  the  field  covering  subway  and  elevated 
construction.  Has  charge  of  construction  work  amounting  to 
from  J30.000.000  to  $35,000,000. 

DIVISION  ENGINEER  OF  SEWERS — In  charge  of  Sewer 
Division,  having  direct  charge  of  the  preparation  of  designs 
and  plans  and  supervision  in  the  field  over  all  sewer  recon- 
struction work  resulting  from  subway  or  elevated  construc- 
tion. 

ENGINEER  OF  SUBSURFACE  STRUCTURES— In  charge 
of  the  Division  of  Subsurface  Structures.  In  direct  charge  of 
the  preparation  of  all  designs  and  plans  covering  the  recon- 
struction and  readjustment  of  all  subsurface  structure  work 
in  connection  with  the  construction  of  subway  and  elevated 
lines. 

GENERAL  INSPECTOR  OF  MATERIAL  —  Has  direct 
charge  over  the  inspection  of  all  materials  of  construction. 

SENIOR  ASSISTANT  DIVISION  ENGINEER— In  charge  of 
administrative  work  of  a  field  division,  under  the  Division 
Engineer.  Acts  as  Division  Engineer  in  the  absence  of  Divi- 
sion Engineer. 

ASSISTANT  DIVISION  ENGINEER— In  direct  charge  of  a 
subdivision  of  field  work  under  the  Division  Engineer  con- 
sisting of  four  contract  sections  of  subway  or  elevated  con- 
struction, covering  work  amounting  to  from  $10,000,000  to 
$12, 000, 00ft. 

ASSISTANT  DIVISION  ENGINEER— In  charge  of  Esti- 
mates Division,  under  the  Deputy  Engineer  of  Subway  Con- 


OKGANIZATION  CIIAUT  OK  TIIK  SEWEI:  DIVISION  OF  THE 
PUBLIC  SERVICE  COMMISSION 

struction,  having  direct  charge  of  the  compilation  and  prepa- 
ration of  Chief  Engineer's  determinations  with  respect  to  the 
cost  of  construction  and  cost  of  equipment  of  all  railroads 
constructed  by  the  City  and  by  the  operating  companies  under 
the  Dual  Contracts  and  Certificates. 

SENIOR  DESIGNING  ENGINEER — In  charge  of  adminis- 
trative work  of  Designs  Division,  under  Principal  Assistant 
Engineer.  Acts  as  Principal  Assistant  Engineer  in  the  ab- 
sence of  Principal  Assistant  Engineer. 

DESIGNING  ENGINEER— In  charge  of  a  subdivision  In 
the  Designs  Division,  under  the  Principal  Assistant  Engineer, 
having  direct  charge  over  the  designing  of  subway  and 
elevated  work  and  the  examination  of  designs  and  plans  pre- 
pared by  the  operating  companies. 

ASSISTANT  DESIGNING  ENGINEER — Assistant  to  De- 
signing Engineer  in  the  Designs  Division.  Acts  as  Designing 
Engineer  in  the  absence  of  the  Designing  Engineer. 

DESIGNING  ARCHITECT — In  direct  charge  of  the  archi- 
tectural design  in  connection  with  subway  and  elevated  work 
under  the  Principal  Assistant  Engineer. 

SENIOR  ASSISTANT  DESIGNING  ARCHITECT — In  charge 
of  administrative  work  in  connection  with  designing,  under 
Designing  Architect.  Acts  as  Designing  Architect  in  the  ab- 
sence of  Designing  Architect. 

ASSISTANT  DESIGNING  ARCHITECT — In  direct  charge 
of  a  subdivision,  under  the  Designing  Architect,  in  the  de- 
signing work  and  the  examination  of  designs  and  plans  pre- 
pared by  the  operating  companies. 

ASSISTANT  ENGINEER — In  direct  charge  in  the  field  of 
the  details  of  construction  of  one  contract  section  of  sub- 
\\ny  or  elevated  work,  under  the  Assistant  Division  Engineer, 
approximating  $1,000.000  to  $3,000,000  in  cost. 

JUNIOR    ENGINEER — Has    charge    of    the     administrative 


work  of  a  contract  section  or  of  a  field  party  giving  lines 
and  grades,  under  Assistant  Engineer. 

DESIGNER — In  charge  of  a  squad  of  Draftsmen  and 
Junior  Assistants  in  computing  and  preparing  designs  and 
plans,  under  Assistant  Designing  Engineer. 

DRAFTSMAN — Does  detail  work  in  preparing  designs  and 
plans,  under  Designer. 

ARCHITECTURAL  DESIGNER — In  charge  of  a  squad  of 
Architectural  Draftsmen  and  Junior  Assistants  in  computing 
and  preparing  architectural  designs  and  plans,  under  Assist- 
ant Designing  Architect. 

ARCHITECTURAL  DRAFTSMAN— Does  detail  work  in 
preparing  architectural  designs  and  plans,  under  Architectu- 
ral Designer. 

JUNIOR  ASSISTANT — Acts  as  a  member  of  field  party  giv- 
ing lines  and  grades,  under  Junior  Engineer;  or  does  detail 
work  on  tracings,  plans,  etc.,  under  Draftsman  or  Architect- 
ural Draftsman. 

CHEMIST — Makes  chemical  analyses  of  materials,  under 
the  General  Inspector  of  Material. 

CEMENT  TESTER — Tests  cements,  under  the  General  In- 
spector of  Material. 

INSPECTOR  OF  STEEL — Inspects  the  manufacture  and 
fabrication  of  steel  at  the  mills  and  shops  and  the  erection 
of  the  steel  in  the  field,  under  the  General  Inspector  of  Ma- 
terial. 

INSPECTOR  OF  CONDUITS — Inspects  the  manufacture  of 
conduits,  under  the  General  Inspector  of  Material. 

CHIEF  CLERK — Secretary  to  Chief  Engineer.  Has  direct 
supervision  over  Engineering  Department  general  files  and 
clerical  and  stenographic  work  in  the  general  office,  under  the 
Deputy  Engineer  of  Subway  Construction. 

ASSISTANT  CHIEF  CLERK — Has  charge  of  filing  and 
clerical  work  under  Chief  Clerk. 

The  lowest  engineering  grade  is  that  of  Junior  A-- 
feistant,  with  an  entrance  salary  of  $901,  with  promotion 
to  $1200  without  change  of  rank.  By  passing  the  re- 
quisite examinations  and  fulfilling  the  efficiency  condi- 
tions, the  Junior  Assistant  is  eligible  to  the  position  of 
Junior  Engineer  at  a  salary  of  $1201  to  $1800,  or  the 
same  rank  in  the  drafting-room  force,  and  so  on;  so  that 
a  capable  man  is  assured  of  reasonable  progress  as  his 
value  increases.  The  Junior  Assistant  corresponds  to 
the  rank  of  axman,  rodman,  chainman,  etc.,  in  other  city 
work,  but  is  better  paid. 

DIVISION  ORGANIZATION — Each  field  division  in  itself 
requires  an  elaborate  suborganization,  as  shown  in  the 
chart.  The  organization  chart  for  the  sewer  division 
will  also  serve  as  an  example  to  illustrate  how  the  military 
scheme  is  followed  out  in  more  detail.  There  are  at  pres- 
ent five  field  Division  Engineers,  each  with  such  a  semi- 
independent  organization  as  shown.  Each  field  division 
comprises  approximately  $25,000,000  to  $30,000,000  in 
work,  the  division  being  so  made  rather  than  to  contain 
a  certain  mileage  or  a  geographical  district. 

The  field  divisions  are  subdivided  as  follows:  three 
subdivisions,  each  in  direct  charge  of  an  Assistant  Di- 
vision Engineer;  each  subdivision  into  four  sections, 
each  comprising  a  normal  contract  of  from  $1,000,000 
to  $3,500,000,  each  section  being  in  charge  of  an  Assi-t- 
ant  Engineer.  The  sections,  like  the  divisions  and  sub- 
divisions are  groups  of  construction  work  of  approxi- 
mately the  same  character  or  cost,  rather  than  divisions  of 
length.  Each  Assistant  Engineer  has,  under  the  full  or- 
ganization scheme,  4  Junior  Engineer  assistants,  and  the  4 
Junior  Engineers  have  5  Junior  Assistants,  the  lowest  en- 
gineering grade  on  the  staff.  A  section  usually  covers  a 
distance  of  from  2000  to  3000  lin.ft.  of  trackway. 

Besides  the  salaried  engineering  staff  of  each  division, 
there  are  about  two  masonry  inspectors  of  construction 
to  each  section,  who  are  paid  $4.50  to  $5.50  per  day,  and 
who  are  not  included  in  the  organization  scheme.  The 
inspectors  report  to  the  Assistant  Engineers  in  r-harge  of 
their  respective  sections. 


[9] 


A  similar  scheme  of  subdivision  exists  in  the  office  di- 
visions of  inspection  of  material,  subsurface  structures, 
station  finish  and  estimates,  and  the  divisions  of  design 
and  of  sewers.  The  various  designers  and  draftsmen  are 
divided  into  groups  and  squads  in  charge  of  Division 
Engineers,  Assistant  Division  Engineers,  Designers,  etc., 
with  ranks,  grades  and  salaries  corresponding  to  the 
field  positions.  Positions  such  as  the  one  previously 
noted  for  Assistant  Division  Engineer  are  usually  open 
to  both  field  and  office  men,  so  it  is  possible  for  a  man 
to  be  promoted  from  office  to  field,  or  vice  versa. 

WORK  OF  THE  ENGINEERING  STAFF 

It  is  almost  impossible  within  a  brief  space  to  give  an 
adequate  idea  of  the  breadth  and  scope  of  the  engineer- 


other  subsurface  structures,  the  passing  upon  all  the 
equipment  for  the  operation  of  the  new  railways,  and 
other  problems  too  numerous  to  mention.  Besides  these 
there  are  the  disposition  of  complaints,  the  maintenance 
of  existing  subsurface  structures  and  street  traffic  to  be 
looked  after  during  the  period  of  construction. 

The  rapid-transit  construction  work  has  been  outlined 
in  15  steps,  as  follows: 

(1)  Preliminary    survey   of   streets   to   be   traversed. 

(2)  Preparation   of  route  maps  and    resolutions. 

(3)  Application  to  and  approval  by  the  Board  of  Estimate 
and    the   Mayor. 

(4)  Consent  of  property  owners  or  of  the  Appellate  Divi- 
sion. 

(5)  Survey   of  surface  and   subsurface    structures. 

(6)  Preparation   of  contract  plans. 

(7)  Preparation  of  form  of  contract. 


0         / 


Chief    Engineer    (center).    Engineer   of    Subway    Construction    (right).   Deputy   Engineer   Subway   Construction    (left),    of   the 

Public    Service    Commission,    First    District,    New    York. 


ing  work  the  Public  Service  Commission's  engineers  are 
called  upon  to  perform.  The  rapid-transit  work  alone 
requires  careful  surveys  of  the  streets  and  subsurface 
structures,  the  examination  of  buildings  before  and  dur- 
ing the  construction  of  subways  on  account  of  the  possi- 
bility of  damages,  the  preparation  of  contract  and  detail 
plans,  the  examination  of  steel  plans,  the  testing  and  in- 
spection of  materials  such  as  cement  and  steel  at  the 
mills  where  they  are  manufactured,  the  close  supervision 
of  the  construction  work  as  it  progresses,  the  preparation 
of  the  estimates  upon  which  the  payments  to  contractors 
are  made,  the  redesign  and  construction  of  sewers  and 


(8)  Public  hearing  on  form  of  contract. 

(9)  Approval  of  form  of  contract  by  Corporation  Counsel. 

(10)  Advertisement  for  and  receipt  of  bids. 

(11)  Acceptance  of  bids  and  submission   to  Board  of  Esti- 
mate for  approval  and  appropriation. 

(12)  Execution  of  contract  and  commencement  of  work. 

(13)  Preparation    of    working    plans    and    examination    of 
the  working   steel   plans. 

(14)  Preparation   of   record    plans. 

(15)  Arbitration   of  disputed   items   of   cost. 

The  rapid-transit  construction  work  cannot  be  com- 
pared with  the  work  of  any  other  commission  in  this 
country  except  the  Boston  Rapid  Transit  Commission, 
but  it  must  be  remembered  that  besides  construction 


[10] 


work,  the  Public  Service  Commission  of  the  First  Dis- 
trict also  performs  the  regulatory  work  of  supervising 
all  the  public  services  of  the  Greater  Xew  York  District, 
the  transportation,  gas  and  electric  businesses  of  which 
amounts  to  about  20%  of  the  total  for  the  entire  United 
States.  The  number  of  passengers  carried  annually  on 
*he  existing  transportation  lines  in  the  city  is  some  60% 
more  than  the  number  carried  by  all  the  steam  railways 
of  the  country. 

ELECTRICAL  EXGIXEEK — The  Electrical  Engineer, 
Clifton  W.  Wilder,  maintains  a  bureau,  not  shown  on  the 
organization  chart,  employing  about  60  engineering  as- 
sistants. His  work  is  divided  into  four  main  divisions 
as  follows:  (1)  Passing  on  all  plans  for  the  electrical 
equipment:  (2)  cost  accounting  of  equipment;  (3)  su- 
pervision of  operation  of  the  existing  lines;  (4)  valuation 
of  public-utility  corporation  properties.  On  the  first  two 
divisions,  as  a  part  of  the  new  subway  construction,  lie 
reports  to  the  Chief  Engineer,  but  on  the  supervision  of 
operation  and  valuation  work  he  reports  directly  to  the 
Public  Service  Commission  as  its  Electrical  Engineer. 
He  has  one  Principal  Assistant  Engineer  and  six  A&- 
.-istant  Engineers.  The  supervision  of  operation  includes 
such  work  as  investigating  complaints  of  equipment,  ac- 
cidents, regular  inspection  of  equipment,  special  investi- 
gations, etc. 

PEHSOXXEI. 

The  scheme  of  an  engineering  organization  plays  only 
a  small  part  in  its  successful  operation.  Much  depends  on 
the  men  who  are  at  the  head  of  it.  The  Chief  Engineer 
of  the  Public  Service  Commission  is  himself  the  kind  of 
man  to  appreciate  the  importance  of  personality  in  the 
efficient  working  of  the  splendid  organization  he  has 
achieved;  and  he  not  only  takes  a  kindly  interest  in  his 
many  subordinates  and  makes  himself  accessible  to  them, 
but  has  so  designed  the  working  of  the  entire  organiza- 
tion as  to  promote  individual  effort,  enthusiasm  and  loy- 
alty. 

ALKUKD  CRAVKX 

The  Chief  Engineer  of  this  great  organization,  which 
at  present  includes  approximately  1000  engineering  em- 
ployees— and  it  is  growing — is  a  descendant  of  a  distin- 
guished family  of  naval  officers  and  engineers.  He  was 
the  son  of  Rear- Admiral  Thomas  T.  Craven,  who  served 
throughout  the  Civil  War  and  was  afterward  Command- 
ant of  the  Mare  Island  Xavy  Yard.  He  is  a  nephew  of 
Alfred  W.  Craven.  Chief  Engineer  of  the  old  Croton 
Aqueduct,  builder  of  much  of  the  original  sewer  system 
of  lower  Manhattan,  the  Central  Park  Reservoir,  and 
many  other  historic  engineering  works  in  and  about 
Xew  York  City. 

Alfred  Craven  was  born  at  Bound  Brook,  X.  J.,  Sept. 
16,  1846.  At  17  years  of  age.  at  the  height  of  the  Civil 
War  period,  he  was  appointed  to  the  United  States 
Xaval  Academy,  then  conducted  at  X'ewport,  R.  I.  Later, 
after  the  coming  of  peace,  the  Academy  returned  to  An- 
napolis. Md..  where  Mr.  Craven  was  graduated  in  1867. 
After  a  few  years'  service,  and  while  on  the  Pacific 
Coast,  he  retired  from  the  Xavy  with  the  rank  of  Mas- 
ter, to  devote  his  life  to  engineering. 

In  1871,  he  joined  the  California  Geological  Survey. 
Later,  he  was  engaged  in  irrigation  work  in  the  Sacra- 
mento and  San  Joaquin  Valleys,  and  then  began  private 
practice  in  Virginia  City,  where  he  established  a  reputa- 


tion as  a  mining  engineer  in  connection  with  the  develop- 
ment of  the  famous  Comstock  lode.  On  this  work  he 
was  associated  with  Adolph  Sutro  in  the  construction  of 
the  well  known  Sutro  tunnel. 

Mr.  Craven  returned  East  in  1884  to  become  Division 
Engineer  of  the  new  Croton  Aqueduct  for  the  additional 
water  supply  for  the  City  of  Xew  York,  where  he  was  in 
charge  of  a  construction  division  and  later  of  the  Carmel 
and  Titicus  dams  and  reservoirs.  On  this  work  he  estab- 
lished an  enviable  reputation  for  rugged  honesty  in  the 
midst  of  graft  and  corruption  on  the  part  of  contractors 
and  politicians.  After  some  straightforward  and  unim- 
peachable testimony  before  a  legislative  committee,  an 
incensed  politician  is  said  to  have  told  Mr.  Craven. 
''You've  done  the  last  stroke  of  work  you  ever  will  do  on 
tin's  job."  Whereat,  Mr.  Craven  is  said  to  have  quietly 
replied,  "I'll  be  here  when  you're  all  gone" — which 
proved  correct,  for  the  Aqueduct  Commission  was  sub- 
sequently reorganized  by  Mayor  Hewitt,  and  "men  of  a 
caliber  to  appreciate  honest  service  were  appointed. 

For  eleven  years,  Mr.  Craven  was  Division  Engineer 
on  the  Croton  Aqueduct  and  Reservoirs,  and  then  in 
1895  he  was  placed  in  charge  of  the  construction  of  the 
Jerome  Park  Reservoir.  Following  a  change  in  the  En- 
gineering Staff  of  the  Commission,  the  plans  of  the  work 
were  altered  in  a  way  which  did  not  meet  with  Mr. 
C raven's  approval  and  early  in  1900  he  was  transferred 
to  another  division  of  the  work.  For  what  happened  af- 
terwards at  Jerome  Park,  he  is  in  no  way  responsible. 

In  May,  1900,  when  the  first  Xew  York  City  subways 
were  begun.  Mr.  Craven  joined  the  engineering  staff  of 
the  Rapid  Transit  Commission  as  Division  Engineer,  in 
charge  of  construction  of  the  division  from  Forty-first 
St.  and  Park  Ave.  through  Forty-second  St.  and  up 
Broadway  to  104th  St.,  the  section  through  Forty-second 
St.  and  under  the  Times  Building  being  one  of  the  most 
difficult  and  delicate  pieces  of  the  whole  work.  He  suc- 
ceeded George  S.  Rice  as  Deputy  Chief  Engineer  of  the 
Rapid  Transit  Commission  in  1904,  when  Mr.  Rice  be- 
came Chief  Engineer,  and  succeeded  to  the  office  of  Dep- 
uty Engineer  of  Subway  Construction  under  Mr.  Rice, 
when  the  Public  Service  Commission  was  organized  in 
1907.  In  1910,  Mr.  Craven  succeeded  H.  B.  Seaman  as 
Chief  Engineer  of  the  Commission. 

Mr.  Craven  has  not  only  distinguished  himself  in  his 
44  years  of  varied  experience  as  a  great  engineer  and 
executive,  but  has  gained  a  reputation  as  an  arbiter  and 
peacemaker  in  solving  the  intricate  problems  in  relation 
to  the  control  and  operation  of  the  dual  transit  system 
now  under  construction.  For  days  at  a  time  he  has  ap- 
peared as  a  witness  at  the  hearings  of  the  Commission 
and  of  the  courts  and  has  won  the  respect  of  lawyers, 
capitalists,  railway-operating  officers,  and  commissioners, 
not  only  by  the  breadth  and  accuracy  of  his  technical 
knowledge,  but  by  the  clearness  and  force  with  which  he 
presented  it. 

ROBERT  RIDGWAY 

Mr.  Craven's  first  lieutenant,  Robert  Ridgway.  was 
born  in  Brooklyn,  X'.  Y.,  Oct.  19,  1862.  He  lived  in 
Brooklyn  and  on  a  Xew  Jersey  farm  until  he  was  19 
years  of  age.  He  never  attended  a  college  or  technical 
school. 

In  May,  1882,  he  went  West  and  joined  the  engineer 
corps  of  the  Xorthern  Pacific  Ry..  serving  as  chainman, 
rodman  and  leveler  on  preliminary  surveys  in  Montana. 


and  on  location  and  construction  in  Wisconsin.  Mr. 
Eidgway  returned  to  the  East  in  the  summer  of  1884 
to  accept  a  position  as  a  leveler  with  the  Croton  Aqueduct 
Commission,  New  York  City. 

For  16  years  he  was  a  member  of  the  Commission's  en- 
gineering staff.  His  first  important  assignment  was  as 
Assistant  Engineer  in  charge  of  the  construction  of  the 
gate-house  and  appurtenances  at  the  Croton  dam  and 
the  northerly  1^  miles  of  the'  new  Croton  Aqueduct, 
from  1886  to  1890.  On  the  practical  completion  of  this 
work  he  was  made  Assistant  Engineer  of  Construction 
of  Reservoir  M  and  appurtenances,  on  the  Titicus  River, 
which  included  the  construction  of  a  masonry  dam  hav- 
ing a  maximum  height  of  130  ft.,  with  earth  wings  100 
ft.  in  height.  Subsequently,  he  was  Assistant  Engineer 
in  charge  of  the  construction  of  the  Jerome  Park  reser- 
voir, serving  there  under  his  present  chief.  Mr.  Craven, 
who  was  Division  Engineer. 

He  followed  his  chief  to  the  Rapid  Transit  Commis- 
sion in  1900  as  his  Senior  Assistant  Engineer  on  the  Sec- 
ond division.  In  March,  1903,  Mr.  Ridgway  was  pro- 
moted to  be  Division  Engineer  and  was  placed  in  charge 
of  the  Fifth  division,  including  the  construction  of  the 
South  Ferry  loop,  the  tunnels  under  the  East  River  from 
the  Battery  to  Brooklyn  and  the  Brooklyn  subway. 

When  the  Board  of  Water  Supply  was  organized  in 
1905  for  the  construction  of  an  additional  system  for 
the  water-supply  of  New  York  City,  he  joined  the  staff 
of  its  Chief  Engineer,  J.  WTaldo  Smith,  as  Division  En- 
gineer, and  was  promoted  the  following  spring  to  the 
position  of  Department  Engineer  in  charge  of  the  North- 
ern Aqueduct  Department,  which  included  the  location 
and  construction  of  the  upper  60  miles  of  the  Catskill 
Aqueduct.  The  Hudson  River  crossing  at  Storm  King 
mountain  was  in  his  department.  Here  he  continued 
until  the  practical  completion  of  most  of  the  work  under 
construction,  in  January,  1912,  when  he  was  again  called 
to  serve  under  his  former  chief,  Mr.  Craven,  with 'the 
Public  Service  Commission. 

DANIEL  LAWRENCE  TURNER 

Daniel  Lawrence  Turner  was  born  in  1869.  He  grad- 
uated from  Rensselaer  Polytechnic  Institute  with  the  de- 
gree of  C.  E.  in  1891. 

For  a  year  he  was  assistant  in  mathematics  at  the  In- 
stitute, and  then  for  three  years  he  was  Assistant  Engi- 
neer in  charge  of  the  location  and  construction  of  a  stand- 
ard-gage switchback  railway  near  Middletown,  Conn.,  for 
the  Columbia  Granite  Co. 

In  1893,  he  was  engaged  in  railway  location  work  and 
as  Engineer  for  Ernest  Flagg,  Architect,  New  York 
City.  For  nine  years  following,  Mr.  Turner  was  Instruc- 
tor in  surveying,  railway  engineering  and  hydraulics  at 
Harvard  University.  While  at  Harvard  he  inaugurated 
the  Harvard  engineering  camp  and  established  and  con- 
ducted for  a  number  of  years  the  present  camp  at  Squani 
Lake,  N.  H.  During  this  period,  he  was  also  engaged  in 
private  practice  with  special'  reference  to  hydraulic  engi- 
neering. 

Mr.  Turner,  like  his  chief  and  Mr.  Ridgway,  is  also  a 
pioneer  New  York  City  subway  engineer.  His  experi- 
ence in  this  work  dates  from  the  beginning  of  the  sub- 
way work  in  1900  when  he  became  a  member  of  the  engi- 
neering staff  of  the  Rapid  Transit  Commission.  During 
the  life  of  the  Rapid  Transit  Commission  1900-1907,  he 


served  in  various  capacities,  first  on  the  preparation  of 
drainage  plans,  as  Assistant  Engineer  in  charge  of  sta- 
tions and  in  charge  of  surveys  for  subway  extension  to 
Brooklyn,  including  the  East  River  triangulation.  Later 
he  was  Division  Engineer  in  charge  of  stations. 

Upon  the  establishment  of  the  Public  Service  Com 
mission,  First  District,  in  1907,  Mr.  Turner  became  Di- 
vision Engineer  of  Stations  and  Chief  of  the  Bureau  of 
Transit  Inspection,  in  which  latter  position  he  originated 
and  formulated  the  methods  of  supervising  the  operation 
of  the  various  street  railways  coming  under  the  Public 
Service  Commission's  jurisdiction.  For  a  year  he  was 
Division  Engineer  of  the  Seventh  division  of  the  new 
subways,  and  since  1912  he  has  been  Deputy  Engineer  of 
Subway  Construction. 

DIVISION  ENGINEERS 

Sverre  Dahm,  Principal  Assistant  Engineer  in  charge 
of  the  Division  of  Design,  was  born  in  Norway,  in  1858. 
His  technical  education  was  received  at  the  Poly  tech- 
nician, Munich,  Bavaria.  He  began  his  engineering  ex- 
perience as  an  Assistant  Engineer  on  the  Norwegian 
Government  railways.  His  first  work  in  America  was  as 
Assistant  Engineer  for  Theodore  Cooper,  Consulting  En- 
gineer, New  York  City.  Subsequently  he  was  in  bridge 
and  structural  work  with  the  Long  Island  R.R.,  and 
with  contractors  in  Chicago  and  New  York  City,  until 
June,  1900,  when  he  was  appointed  Assistant  Engineer 
of  the  Rapid  Transit  Commission.  Since  then  he  has 
passed  through  various  grades  in  the  Rapid  Transit  Com- 
mission and  its  successor,  the  Public  Service  Commis- 
sion, and  since  1909,  has  been  Principal  Assistant  Engi- 
neer. 

Frederick  W.  Carpenter,  Division  Engineer  of  con- 
struction, was  born  in  1859,  and  graduated  from  Cornell 
University  in  1884.  For  10  years  he  was  in  railway 
construction  and  municipal  work  in  the  East  and  Middle 
West.  In  1895  he  was  appointed  Assistant  Engineer, 
Bureau  of  Highways,  Brooklyn,  N.  Y.,  where  he  re- 
mained until  1900,  when  he  became  Assistant  Engineer 
of  the  Rapid  Transit  Commission.  He  continued  as  As- 
sistant Engineer  of  the  Public  Service  Commission,  and 
in  1910  was  promoted  to  be  Senior  Assistant  Division 
Engineer,  and  Division  Engineer  in  1913. 

John  H.  Myers,  Division  Engineer  of  construction,  was 
born  in  1869  and  graduated  from  Rensselaer  Polytechnic 
Institute  in  1893.  After  a  few  years'  experience  in  gen- 
eral surveying  and  engineering  work  in  and  about  New 
\ork  City,  he  spent  six  years  as  Assistant  Engineer  with 
the  Department  of  Water  Supply  of  Brooklyn,  N.  Y.  In 
1900  he  joined  the  engineering  staff  of  the  Rapid  Tran- 
sit Commission  as  Assistant  Engineer,  and  in  1906  he 
was  promoted  to  be  Division  Engineer,  which  office  he 
continued  to  hold  under  the  Public  Service  Commis- 
sion. 

Frederick  C.  Noble,  Division  Engineer  of  construc- 
tion, is  a  son  of  the  late  Alfred  Noble.  He  was 
born  in  1872  and  graduated  in  civil  engineering  at  the 
I' Diversity  of  Michigan  in  1894.  Most  of  his  experi- 
ence until  1900  was  in  bridge  and  structural  work.  He 
entered  the  service  of  the  Rapid  Transit  Commission  as 
a  draftsman  in  June,  1900.  He  was  promoted  to  be  As- 
sistant Engineer  the  following  summer  and  to  be  Division 
Engineer  in  1905.  Mr.  Noble  has  had  immediate  super- 
vision of  the  design  and  preparation  of  contracts  and  spe- 


[12] 


cifications  for  the  four  East  River  tunnels  for  which  con- 
tracts have  recently  been  awarded.* 

Cornelius  V.  V.  Powers,  Division. Engineer  of  construc- 
tion, was  born  in  1860.  He  is  a  graduate  of  the  Colum- 
bia University  School  of  Mines  and  his  first  experience 
was  as  Chemist  and  Metallurgist  for  a  smelting  company. 
His  civil  engineering  experience  began  as  a  laborer  with 
the  Xew  Croton  Aqueduct  Commission  in  1885.  He  was 
successively  promoted  through  subordinate  positions  to  be 
Assistant  Engineer.  In  1900  he  joined  the  staff  of  the 
Rapid  Transit  Commission  as  Assistant  Engineer.  He 
was  promoted  to  be  Division  Engineer  in  1903. 

Jesse  0.  Shipman,  Division  Engineer  of  construction, 
was  born  in  1868.  He  graduated  from  Bucknell  Univer- 
sity, Pennsylvania,  in  1890.  The  first  10  years  of  his 
engineering  experience  were  spent  mostly  in  railway  sur- 
vey and  construction  work.  In  June,  1900,  he  was  ap- 
pointed transitmaii  with  the  Rapid  Transit  Commission 
and  a  year  later  Assistant  Engineer.  In  April,  1910,  he 
was  promoted  to  be  Senior  Assistant  Division  Engineer 
and  in  October,  1911,  Division  Engineer. 

Louis  D.  Fouquet,  Division  Engineer  of  Sewers,  was 
horn  in  1867.  He  was  in  railway  work  in  the  East.  From 
1904  to  1908,  he  was  Assistant  Engineer  of  the  Xew 


•Mr.  Noble  resigned  as  Division  Engineer  of  the  Public 
Service  Commission  to  take  up  the  consulting  work  of  his 
father,  the  late  Alfred  Noble. 


York,  Xew  Haven  &  Hartford  R.R.,  and  had  charge  of 
construction  of  two  large  Scherzer  rolling  lift  draw 
bridges,  one  four-track  and  the  other  six-track.  He 
joined  the  staff  of  the  Public  Service  Commission  in 
1908  as  Division  Engineer. 

The  Division  Engineer  in  charge  of  Subsurface  Struc- 
tures is  C.  N.  Green,  and  George  L.  Lucas  is  Division 
Engineer  in  charge  of  Inspection  of  Materials  and  Con- 
struction. 

ELECTRICAL  ENGINEER 

The  Electrical  Engineer  of  the  Public  Service  Com- 
mission, Clifton  W.  Wilder,  was  born  in  Leominster, 
Mass.,  in  1876,  and  graduated  from  the  Massachusetts 
Institute  of  Technology  in  1898.  For  several  years  he 
was  engaged  in  various  kinds  of  electrical  and  mechan- 
ical engineering  in  and  about  Boston  and  New  York 
City.  He  first  became  connected  with  Xew  York  City 
electric  railway  work  in  April  1905,  as  Assistant  Engi- 
neer of  Construction  with  the  Xew  York  City  Interbor- 
ough  Railway  Co.  He  joined  the  staff  of  the  Public 
Service  Commission  in  Xovember,  1907,  as  Assistant 
Electrical  Engineer,  becoming  the  head  of  the  depart- 
ment in  1909.  This  position  requires  not  only  wide 
technical  knowledge  and  experience  in  electrical  engi- 
neering, but  also  the  ability  to  appear  as  an  advocate 
and  expert  at  public  hearings  of  the  Commission. 


[13] 


^  J[|j  Tlhe  ©persiMinigf  Contracts 


Stated  briefly,  the  original  contract*  for  the  present 
subway  provided  for  its  construction  by  the  city  or  with 
the  city's  money,  its  equipment  of  power  stations,  elec- 
trical apparatus,  signals,  telephones,  rolling  stock,  etc., 
being  furnished  by  the  operating  company,  which  had 
a  lease  for  50  years,  with  privilege  of  renewal  for  25 
more.  Contract  2,  Brooklyn  extension,  was  for  35  and 
2~>  years.  These  two  contracts  with  the  renewals  would, 
therefore,  run  to  19 79  and  1965,  respectively.  The 
operating  company  was  to  pay  a  rental  sufficient  to  cover 
the  interest  and  amortization  on  the  bonds  issued  by 
the  city  in  payment  of  the  cost  of  construction.  At  the 
end  of  the  lease,  the  city  to  own  the  structure  free  and 
dear,  with  the  right  to  purchase  the  equipment. 

The  elevated  lines  in  Manhattan  have  a  perpetual 
franchise,  so  that  under  the  new  arrangement,  the  lease 
for  the  extensions  to  these  lines  and  the  third  tracks  was 
made  to  run  for  85  years,  and  is  not  included  in  the  agree- 
ment covering  the  other  lines. 

By  the  terms  of  the  new  contracts,  the  leases  of  all 
the  new  lines  as  well  as  those  of  the  existing  subway 
are  to  run  for  49  years  from  Jan.  1,  1917,  and  provide 
that  the  city  shall  shave  in  the  profits  of  operation, 
which  are  to  be  determined  in  the  following  manner : 

The  revenues  of  all  operated  lines  of  each  system  will 
be  pooled,  the  two  companies  will  be  allowed  to  retain 
all  the  earnings  (after  payment  of  rentals,  interest, 
amortization,  etc.)  on  the  lines  they  now  operate,  and 
the  city  will  share  in  the  profits  of  the  rest.  The  con- 
tracts provide  for  quarterly  settlements,  which  will  pro- 
vide for  the  following  payments  :f 


into    the  depreciation   funds  and   if  any   excess  occurs,   it  may 
be  withdrawn   from  such   funds. 

5.  (Interborough  Contract).  For  the  first  year  of  opera- 
tion an  amount  equal  to  5  per  cent,  of  the  revenue  for  deprecia- 
tion of  such  portions  as  are  not  repaired  or  replaced  through 
expenditures  for  maintenance.  Two  depreciation  funds  are 
established — one  for  the  existing  subway,  and  one  for  the 
new  lines,  and  they  will  be  under  the  control  of  the  Depre- 
ciation Fund  Board.  Depreciation  for  future  years  to  be 
agreed  upon. 

5.  (Brooklyn   Contract).     For   the  first  year  of  temporary 
operation  an  amount  equal   to   3   per  cent,   of  the  year's  reve- 
nue   for    depreciation    of    such    portion    of    roads    and    equip- 
ment   as    are    not    repaired    or    replaced    through    expenditures 
for    maintenance.      This    amount    for    each    year    will    be    paid 
into    three    depreciation    funds — "Depreciation    fund    for    the 
railroad    and    equipment,"    "Depreciation    fund    for    the    plant 
and    property    of    the    extensions    and    additional    tracks,"    and 
"Depreciation    fund   for   existing   railroads."    Such    funds   shall 
be    under    the   control    of   the    Depreciation    Fund    Board.      De- 
preciation   for   future   years   to  be   agreed   upon. 

The  Depreciation  Fund  Board  is  to  consist  of  three  mem- 
bers— one  to  be  chosen  by  the  company,  one  by  the  Commis- 
sion and  the  third  by  both  jointly,  or  in  case  of  failure  to 
agree,  by  the  Chief  Judge  or  an  Associate  Judge  of  the  Court 
of  Appeals,  or  by  the  President  of  the  Chamber  of  Com- 
merce. 

6.  (Interborough    Contract).      One-quarter    of    the    sum    of 
$6.335,000  to  be  retained  by  the  company,  as  representing  the 
average    annual    income    from    the    operation    of    the    existing 
railroads. 

6.  (Brooklyn    Contract).      One-quarter   of   the   sum    of   $3,- 
500,000    to    go    to    the    company    "as    representing    the    average 
annual    income    from    the    operation    of   the    existing    railroads 
during   the  two  years  prior   to   the   beginning   of  initial  oper- 
ation,  out   of  which   the   lessee   shall   pay   interest   charges  on 
obligations    representing    the    capital    investment     (preceding 
the  date  of  this  contract)  on  the  existing  railroads." 

7.  One-quarter  of  an   amount  equal   to   6   per  cent,    of  the 
company's    contribution    toward    the   cost   of   construction   and 
equipment    for    initial    operation.      Out    of    this    payment    the 
company   must  set  aside  amounts  sufficient,  with  interest  and 


woo 


EOOO'         3000'         4000'        5000' 


FIG.  7.     PROFILE  OF  THE 


1.  To  the  City  (in  the  Interborough  contract  only)   rentals 
now    required    to   be   paid    under  Contract  No.    1    and   Contract 
No.    2,   such    rentals    to  continue    through    the   life   of  the  new 
contract;  also   (in  case  of  both  companies)   such  rentals  actu- 
ally payable  by   the  company  for  the  use  of  property   in  con- 
nection   with    the    system,    such   as  are   not   included    in   oper- 
ating expenses. 

2.  Taxes  and    governmental    charges   of  every   description 
against  each  company  in  connection  with  the  system. 

3.  All    expenses,    exclusive    of    maintenance,    actually    and 
necessarily   incurred   by   either   lessee   in    the    operation   of   its 
system. 

4.  Twelve    per    cent,    of    the    quarter's    revenue    for    main- 
tenance,   exclusive    of    depreciation.      "Maintenance"    shall    in- 
clude repair  and   replacement  of  tracks,   but  not   the   replace- 
ment  of   any    principal    part   of   structure    and    equipment.      If 
the    maintenance  cost  in   any  quarter  year  shall   be   less  than 
12  per  cent,  of  the   revenue,   the  unexpended  balance  shall  go 


•See   "Eng.  News,"  Feb.  13,  1902,  p.   127,  for  details. 
tFrom  pamphlet  issued  by  the  Public  Service  Commission. 


accretions,    to    amortize    within    the    terms    of    the    lease    such 
contribution   and  cost. 

8.  If   additional    equipment    is    provided    an    amount    to    be 
retained   by   the  company   equal   to  one-quarter  of  the   annual 
interest    payable    by    it    upon     the    cost    of     such     additional 
equipment:   together  with  a  sum  equal  to  %  of  1  per  cent,  for 
the  amortization   of  such  cost. 

9.  (Interborough   Contract).      If   the   company    shall    share 
the  cost  of  construction   of  additions   to    the   Dual  System,   an 
amount   equal   to   one-quarter   of  the   annual    interest   payable 
by   the   company    upon    its   share    of   such   cost,    together    with 
V4    of   1    per   cent,    for   amortization. 

9.  (Brooklyn     Contract).      To     be     paid     to     the     city     an 
amount   equal    to   one-quarter   of   the   annual   interest   payable 
by  the  city  upon   its  share  of  the  cost  of  construction   and    % 
of  1  per  cent,  of  the  city's  share  of  such  cost. 

10.  (Interborough    Contract).      An    amount    to    be    paid    to 
the   city  equal   to    >4    of   8.76    per   cent,    of  that   portion   of    the 
cost  of  construction   paid  by  the  city. 

11.  An     amount    to    be    paid    to    the    city    equal     to     one- 
quarter    of    the    annual    interest    actually    payable   by    it    upon 


[14] 


CONTRACT    PRICES    FOR   VARIOUS    SECTIONS   OF    SUBWAY    CONSTRUCTION 


Location 
Broad&ay  Line. 

Morris  to  Dey 

to  Park  Place, 
to  Walker  St.. 

to  Howard 

toBfeecker... 
to  Union  Sq . . . 

to  26th  St 

Varick  Sl.-7th  Aw. 

Vesey  to  Beach 

to  Commerce.. 

to  16th  St 

to  30th  St 

to  42nd  St 


Lexington  Ate. 
53rd  to  67th  St  ..... 

to  79th  St  .................. 

to  93rd  St  .................. 

to  106th  St  .....  '  ..... 

to  118th  St  ................. 

to  129th  St  ................. 

to  135th  St.  (Harlem  River). 

to  157th  St  ................. 

138th  to  147th  St  ................ 

to  Bancroft  ............... 

Completion  Stein  way  Tunnel  ..... 

f  frame  Ate. 

157th  to  182nd  St  ............... 

to  Woodlawn  Road  ........ 

Whitt  Plaint  Road. 

to  Burke  Ave  .............. 

to  241st  St  ................. 


Bridge  Plau  ................... 

Beebe  Ave.  to  Ditmars  Ave  ....... 

Van  Dam  St.  to  Syracuse  Ave  ..... 

Brooklyn, 

4M  AM. 

Man.  Bridge  to  43rd  St.  .  . 
43rd  to  61st  St  .................. 

61st  to  S9th  St  .................. 

\nc  UtrecU  Are. 

39th  to  Ave.  Y  .................. 

*Steel  tReinforced  Concrete. 


Route 

5 
5 
5 
5 
5 
5 
4*36 


44  38 
4  A  38 
4*  38 
4*38 
4*38 


5 
5 
5 
5 
5 
5 
5 
5 

19*22 

19*22 

50 


16 

18 
36*37 

"lib 
39 


Section 

1 

la 

2 

2a 

3 

I 

1 


8 

9 
10 
11 
12 
13 
14 
15 

1 

la 


%    com- 

Contract price 
Per  lin.  ft. 

pleted 
un  Mar. 

Total 

Structure 

Track 

1,  1914 

S 

t 

$ 

% 

1,222,269 

607 

303 

51 

982,741 

954 

472 

31 

2,355,829 

841 

201 

82 

912,352 

1721 

430 

56 

2,295,086 

879 

82 

2,578,078 

658 

"165 

20 

2,056,703 

12 

3,059,522 

940 

268 

2,188,004 

503 

126 

i 

1  837  927 

536 

134 

2,401,307 

673 

168 

'i 

2.292,944 

717 

161 

3,369,484 

913 

215 

66 

1.961,997 

633 

158 

79 

3,253,073 

865 

134 

80 

3,132,195 

911 

226 

S3 

4,071,417 


3,820,130 

_•  253  :>-' 

2,253,159 

557,857 


1,077,978 
1.076,831 

914,400 
958.480 

884.859 
M0.7M 

2,063,588 


16,014,388 
1,930,259 
1,904,171 

1,672,190 


895 
1397 

iaa 

458 
312 


81 

82 


71 
76 


80 
93* 
116t 


346 
240 


71 


224 
228 
361 
183 
105 


27 
27 


24 
25 


91 
109 


24 


86 
60 
41 
81 
12 


97 
22 


36 


Contractor 


F.  L.  Cranford,  Inc. 

Degnon  Contr.  Co. 
O'Rourke  Constr.  Co. 
Und.  *  Found'n  Co. 
Dock  Contr.  Co. 
E.  E.  Smith  Co. 


Degnon 

U.  S.  Realty  Co. 
U.  S.  Realty  Co. 
Rapid  Transit  Constr.  Co. 

Bradley  Contr.  Co. 
Patrick  McGovern  Co. 
Bradley  Contr.  Co. 

Oscar  Daniels. 
MeMullen,  Snare  *  Triest. 
McMullen  *  Hoff. 
Rogers  *  Hagertv. 
Richard  Carvel  Co. 
Rogers  *  Hagerty. 
Degnon 


Oscar  Daniels  Co. 
Cooper  *  Evans 

Oscar  Daniels  Co. 
Alfred  P.  Roth 

Snare  &  Triest  Co. 
Cooper  *  Evans  Co. 
E.  E.  Smith  Co. 


6  sections  completed. 
Carpenter  *  Boxley  4  Herrick 


Post  *  McCord 


its   share    of   the   cost   of  construction   of  additional   lines,    to- 
gether with   %  of  1  per  cent,  for  amortization. 

12.  One  per  cent,  of  the  revenue  to  be  paid  into  a  sepa- 
rate fund  under  control  of  the  Depreciation  Fund  Board  to 
be  invested  and  reinvested  to  provide  a  contingent  reserve 
fund.  When  such  fund  equals  1  per  cent,  of  the  cost  of  con- 
struction and  equipment,  payments  to  it  shall  be  suspended 
and  interest  on  it  shall  be  included  in  the  revenue.  If  it  falls 


and  the  Bronx,  from  west  to  east  in  Brooklyn.  The  sec- 
tions vary  considerably  in  length,  but  are  generally  about 
half  a  mile,  and  the  bids  so  far  obtained  range  from 
about  $800,000  to  $4,000,000  per  section.  The  costs  per 
foot  of  structure  and  track  are  shown  in  the  accom- 
panying table,  which  also  shows  the  per  cent,  of  work 


I  i  I        1      i  I  I  I 


LEXIXGTOX  AVE.  LIKE 


below  1  per  cent.,  payments  shall  be  resumed  until  it  again 
equals  1  per  cent.  This  fund  shall  be  used  to  meet  deficits  in 
operation  and  other  purposes. 

13.  The  amount  remaining  after  making  the  foregoing 
deductions,  shall  be  divided  equally  between  the  city  and 
the  company. 

ROUTE  AXD  SECTION  NUMBERS 

The  custom  was  established  in  the  days  of  the  old 
Rapid  Transit  Commission  of  assigning  a  number  to  the 
various  different  routes  proposed  from  time  to  time  for 
new  lines,  and  this  has  been  perpetuated,  as,  for  instance, 
the  Lexington  Ave.  route  is  Route  5,  etc.  It  seems  hardly 
necessary,  however,  for  the  purpose  of  these  articles  to 
enumerate  these  in  detail. 

For  construction  purposes,  each  route  is  divided  into 
sections,  numbered  consecutively  from  the  beginning  and 
usuallv  from  the  south  toward  the  north  in  Manhattan 


completed  on  each  section  on  Mar.  1,  191-1.  and  the 
names  of  the  contractors.  The  prices  given  in  this  table 
do  not  include  station  finish,  such  as  tiling,  stairways, 
ticket  offices,  railing,  etc.,  or  any  track  or  equipment. 

There  is  very  little  comment  which  can  be  made  on 
these  figures  The  work  is  so  varied  that  there  is,  as 
will  be  seen,  a  wide  variation  in  the  prices  either  per 
lin.ft.  of  track  or  per  lin.ft.  of  structure.  The  Lex- 
ington Ave.  line  is  perhaps  fairly  typical  of  normal 
conditions.  (See  profile.  Fig.  T.)  From  53rd  St.  to 
129th  St.  the  price  is  fairly  uniform  at  about  $225  per 
lin.ft.  of  track.  Sections  9  and  10,  however,  have  two 
tracks  in  tunnel  which  can  be  built  with  little  or  no 
interference  with  subsurface  structures  and  no  street 
support,  and  this  is  reflected  in  the  lower  price.  Sec- 


[15] 


tion  13  has  a  high  price  per  lin.ft.  of  structure,  as  this, 
as  will  be  noted  later,  provides  for  a  very  elaborate  sys- 
tem of  track  crossings.  Section  14  is  the  Harlem  River 
crossing.  The  sections  north  of  the  Harlem,  Eoute  5, 
Section  15,  Eoutes  19  and  22,  Sections  1  and  la,  where 
only  part  of  the  street  is  required  to  be  decked  and  where 
the  street  cars  are  operated  by  the  overhead  trolley,  show 
a  considerable  decrease  in  the  cost  per  foot,  as  do  also 
the  elevated  structures  on  Jerome  Ave.  and  White  Plains 
Eoad. 

On  the  down-town  lines,  Eoute  5  (Broadway),  Section 
1  involves  the  support  of  the  elevated  railroad  structure ; 
Section  la  the  two  reversed  curves  driven  in  tunnel;  Sec- 
tion 2a  the  crossing  of  Canal  St.,  where  the  underground 
conditions  are  very  bad.  The  other  sections,  which  are 
perhaps  more  nearly  normal,  show  approximately  an  ap- 
proach to  the  commonly  accepted  rough  estimate  figure 
of  $1,000,000  per  mile  of  track,  built  in  subway. 

EQUIPMENT 

There  has  been  no  announcement  so  far  of  any  change 
in  type  of  rolling  stock  of  the  Interborough,  but  the 
B.  B.  T.  has  had  a  larger  type  of  car  designed,  Fig.  9, 
providing  considerably  greater  capacity,  which'  will,  it  is 
thought,  owing  to  the  arrangement  of  the  doors,  permit 
such  easy  ingress  and  egress  that  there  will  be  no  more 
delay  in  loading  and  unloading  than  there  is  with  the 
small  cars  now  in  use.  The  principal  dimensions  of 
these  two  cars  are  as  follows : 


B.  R.  T. 

67 
10 


Interborough 

Length  over  all,  ft 51.0 

Width  over  all,   ft 9.5 

Weight    of    empty    car    on    each    axle    of 

motor  truck,  Ib 30,800                    (a) 

Weight  of  the  other  two  axles,  Ib 22,200                     (a) 

Number  of  seats 

Capacity,   sitting  and  standing 175                     270 

(a)   Not  to  exceed  31,000  Ib.   per  axle  when  fully  loaded. 

There  have  been  many  difficulties  to  overcome  in 
connection  with  the  design  of  these  larger  cars.  Axle 
loads  of  31,000  Ib.  cannot  be  exceeded,  as  this  is  fixed 
by  the  bridge  department  for  the  East  Eiver  bridges. 
The  motors  are  arranged  one  on  each  truck,  instead  of 
both  on  one  truck,  as  on  the  present  Interborough  car, 
this,  of  course,  giving  a  better  distribution  of  the  weight 
and  taking  care  of  some  of  the  increase  in  the  weight 
of  the  body  and  number  of  passengers.  The  limitation 
as  to  the  axle  loadings  could  not  be  overcome  by  the 
adoption  of  six-wheeled  trucks,  even  though  their  use 
were  not  prohibited  by  the  sharp  curvature,  as  this  would 
only  involve  a  heavier  truck  with  practically  the  same 
concentration  of  load  so  far  as  the  bridge  structures  are 
concerned. 

Some  important  improvements  are  to  be  introduted 
in  the  equipment  of  the  cars.  The  combined  car  and  air- 
line couplers  (described  in  ENGINEERING  NEWS,  Feb. 
29,  1912)  have  proven  very  satisfactory,  and  in  addition 
to  these  couplers  a  device  is  to  be  installed  in  the  new 
equipment  which  will  also  permit  the  automatic  coupling 
of  the  electrical  connections  (10  in  all).  The  coupling 
and  uncoupling  will  be  entirely  under  the  control  of  the 
motorman  in  the  cab  and  be  governed  by  an  interlock- 
ing device  so  that  the  electrical  connection  cannot  be 
made  until  the  air-line  coupling  is  complete  and  the 
brakes  are  under  control.  Similarly  to  uncouple,  the 
release  of  the  electrical  connection  by  the  motorman 
permits  him  to  release  the  devices  so  that  the  air  and 


train  couplings  will  part.  It  is  hoped  by  these  de\ces 
to  materially  decrease  the  number  of  accidents  to  len 
uncoupling  cars,  and  also  to  reduce  the  time  and  e  rise 
of  making  up  trains. 

Before  the  introduction  of  this  automatic  couplei  lie 
link-and-pin  type  had  been  in  general  use,  but  even  ith 
eight-car  trains  on  the   Interborough,  the  breakin    in 
two  of  the  trains  was  frequent  enough  to  show  thu 
limit  had  been  reached  for  this  type  of  couplings.    Vu- 
tomatic  stops  in  connection  with  the  signals  are  i 
in  the  present  subway,  and  the  sudden  setting  o 
brakes  produces  heavy  stresses  on  the  couplings, 
new  coupler  has  satisfactorily  stood  all  the  strain 
to  these  causes,  and  the  introduction  of   10-car  nins 
made   it  almost  an  absolute  necessity.     Electric 
matic  brake  control  will  be  used  on  the  new  equi] 
insuring  more  nearly  simultaneous  action  of  the  li 
on  all  the  cars. 

The  signal  to  the  motorman  is  given  by  the  e 
of  an  electric  circuit  when  all  the  doors  of  the 
are  closed.     This  has  been  in  use  successfully  for   .nn> 
little  time  already,  and  not  only  saves  the  delay  c 
transmitting  the  signal  from  car  to  car  by  ham"  but 
also  acts  as  a  safety  device  in  preventing  the  st 
of  the  train  while  any  door  is  open. 

A  species  of  weighing  device  has  been  intnxh 
connection   with  the  air-brake   system  to   maintai    the 
same  ratio  of  braking  power  on  loaded  and  empt 
As  the  car  is  stopped  at  the  station,  the  variation  i 
load  due  to  the  discharge  or  receipt  of  passcnjr<      ac- 
tuates  a  piston   in   an   auxiliary   air   cylinder.    • 
connected   to   the   jam-cylinder.     The   variation    i 
position  of  this  piston  in  the  auxiliary  cylinder  n 
the  volume  of  the  jam  cylinder,  thereby  regulatii.1  the 
effective  pressure  obtained  from  a  given  amount  <  air; 
thus  when  the  car  is  fully  loaded  the  volume  of  tli 
iliary  cylinder  is  at  its  minimum,  and  when  the 
empty  it  is  at  its  maximum.    When  the  doors  are 
it  is  automatically  locked  in  this  position  until  tin"  arc 
opened  at  the  next  station,  thus  preventing  any 
from  variations  in  the  loading  due  to  the  vibratio  and 
oscillation  of  the  moving  train. 

A  similar  device  is  to  be  applied  to  the  accelerai 
tern.     At  present  this  has  to  be  adjusted  so  that     will 
not  slip  the  wheels  of  an  unloaded  car.     With  tli  pro- 
posed device,  however,  it  will  be  so  adjusted  thai     will 
be  increased  under  load. 

By  these  various  devices  it  is  expected  to  si  six 
minutes  in  time  between  59th  St.  and  Coney  Islam  De- 
celeration from  50  miles  per  hour  will  be  accomiished 
at  the  rate  of  3  mi.  per  hr.  per  sec.  (on  the  emen-iicy) 
as  compared  with  the  present  maximum  of  2  mi.  :r  hr. 
per  sec.,  and  from  the  lower  rates  of  speed  at  igher 
rates  of  deceleration,  while  acceleration  will  be  ;  the 
rate  of  l1/^  mi.  per  hr.  per  sec. 

Comparison  of  this  with  some  comparatively  ocent 
practice  on  electrified  steam  railroads  is  of  intere 

N.  Y.,  N.  H.  &  H.  R.R.— Multiple  nnit  trains,  motor 
2  trailers,  acceleration  0.5  mi.  per  hr.  per  sec.  8  ;edule 
speed  from  Grand  Central  Station  to  Mt.  Verno.  131/-; 
miles,  with  1  stop  in  28  minutes. 

Lancashire  &  Yorkshire  R.R.,  England — AcceTation 
to  30  mi.  per  hr.  in  30  sec.  Schedule  speed.  18];  miles 
with  14  stops  in  37  minutes. 


[16] 


POWER 

Powe  for  the  Interborough  system  is  to  be  furnished 
from  ti  power  houses  at  59th  St.  and  the  North  River 
and  at '4th  St.  and  the  East  River.  The  former,  built 
to  furnii  power  for  the  present  subway,  was  originally 
equippe  with  nine  reciprocating  units  with  a  total  nor- 
mal cajx-ity  of  7500  kw.  each.  This  was  increased  later 
by  the  adition  of  five  low-pressure  turbines  each  having 
an  addional  capacity  of  7500  kw.  and  using  exhaust 
steam  fnn  the  original  units  to  a  total  of  105,000  kw. 
This  pint  is  now  to  be  enlarged  by  the  addition  of  two 
30,000-lr.  turbine  units,  each  unit  consisting  of  a  high- 
pressurt  high-speed  set  exhausting  into  a  low-pressure 
Icw-spee  turbine,  making  the  total  normal  capacity  about 
165,uiiD  w. 

The  Ith  St.  power  house  was  built  only  13  years  ago 
when  r  '"levated  lines  were  electrified,  but  owing  to  the 
rapid  cfcnge  or  improvement  which  is  continually  tak- 

Sfreef   Surface 

^% 


or  alignment  as  they  affect  economy  of  operation.  The 
primary  consideration,  of  course,  is  the  general  location 
of  the  lines  through  or  under  streets  in  those  sections  of 
the  city  where  the  service  is  needed.  The  second  consid- 
eration is,  the  location  of  the  various  stations,  which,  in 
the  lower  part  of  Manhattan  (below  42d  St.)  are  about 
five  or  six  blocks  (1200  to  1500  ft.),  and  in  the  outlying 
sections  about  2500  ft.  apart,  and  which  is  generally  arbi- 
trarily fixed  by  local  conditions.  Then  the  grades  and 
alignment  (within  certain  fairly  wide  limits)  are  made 
to  fit  these  conditions.  At  present,  owing  to  the  fact  that 
some  sections  of  the  line  are  not  definitely  designed,  it  is 
not  possible  to  make  an  exact  and  complete  statement  cov- 
ering the  gradients  and  alignments  of  the  whole  system, 
but  the  following  is  approximately  correct. 

GRADIENTS — Gradients  up  to  3%  may  be  considered 
normal,  this  upper  limit  being  used  with  considerable  fre- 
quency, though  generally  in  comparatively  short  stretches. 


Section     A~B 
FIG.  8. 


'  InveH-  and   Sidewall  where  Structure  is  entirely  in  Earth 
TYPICAL  SECTION  OF  RAPID  TRANSIT  SUBWAY  ON  SEVENTH  AVE.  AT  23RD  ST. 


ing  plan  in  electrical  machinery  and  apparatus,  part  of 
this  plar  is  to  be  replaced.  The  old  equipment  consisted 
of  eight  nits  (reciprocating)  and  one  turbine  unit  of 
7 "nil i  KV  ach.  Four  of  these  are  to  be  taken  out  and 
three  tuiine  generators  of  30,000  kw.  each  are  to  be  in- 
stalk'ii.  idi.  with  the  five  old  units  remaining,  will 
make  a  ual  normal  capacity  of  127,500  kw. 

The  cotracts  between  the  operating  companies  and  the 
city  call  >r  an  average  speed  on  express  tracks  between 
main-lineterminaJs  of  25  miles  per  hour,  including  stops 
of  30  secods  at  each  intermediate  station,  and  an  average 
speed  on  ><-al  tracks  between  terminals  of  15  miles  per 
hour,  inoiding  stops  of  20  seconds  at  each  intermediate 
station. 

GRADIENTS  AND  ALIGNMENT 

Unlike  lie  location  of  steam  railroads,  the  location  of 
such  line  as  these  under  consideration  is  governed  only 
to  a  conir  ratively  small  extent  by  questions  of  gradient 


Some  of  the  longest  are  nearly  1500  ft.  in  length,  and  in 
a  very  few  cases  3%  grades  as  long  as  this  occur  as  as- 
cending grades  immediately  beyond  a  station  stop  on  the 
local  lines.  There  are  gradients  in  excess  of  this  up  to 
4.5%,  and  in  one  case  where  the  Centre  St.  loop  connects 
to  the  old  Brooklyn  Bridge  it  has  been  necessary  to  use 
5.4%.  The  higher  rates  of  gradient  occur  mostly  in  con- 
nection with  the  approaches  to  the  East  River  Bridges 
or  the  tunnels  under  the  rivers,  the  grades  on  the  former 
being  3.4%  on  the  three  newer  bridges  and  3.75%  on  the 
old  Brooklyn  Bridge. 

With  electrical  operation  and  especially  with  the  dense 
traffic  conditions  which  exist  or  which  will  exist  on  the 
Rapid  Transit  lines  in  New  York,  the  question  of  gradi- 
ents is  not  so  important  as  it  is  in  connection  with  the 
locations  of  railroad  lines  for  operation  by  steam  loco- 
motives, or  where  continuous  sustained  effort  is  required 
on  long  supported  gradients. 


[17] 


For  short  sections  of  heavy  grade,  extra  power  is  sup- 
plied through  an  additional  feed  wire  or  wires  to  the 
points  where  it  is  needed.  The  electric  motor,  as  is  known, 
can  stand  a  heavy  overload  of  as  much  as  100%,  or  even 
more  for  short  periods,  the  amount  of  the  load  and  the 
time  which  it  can  be  carried  being  limited  by  the  heating 
which  takes  place  under  these  conditions.  Short  stretches 
of  steep  gradient  are  not,  therefore,  limiting  or  as  im- 
portant as  longer  ones  would  be.  Considering  the  re- 
quirements for  some  reserve  power  for  ordinary  operation 
which  have  to  be  fairly  liberal,  on  account  of  the  great 
seriousness  of  any  delay  as  well  as  the  short  distance 
between  stations,  it  can  be  seen  that  the  limits  con- 
trolling the  gradients  which  may  be  used  are  rather 
wide. 

In  the  operation  of  self-contained  motor  cars  also, 
there  is  the  advantage  over  trains  hauled  by  locomotives 
that  all  additional  load  increases  the  adhesion  and,  there- 
fore, permits  application  of  the  power  necessary  to  haul 
it.  It  may  also  be  noted  that  the  new  motors  are  to  be 
artificially  cooled  by  blowers. 

The  general  procedure  has  been  that  the  gradients  are 
fixed  by  local  conditions  within  the  limits  given  above, 


depressions  even,  or  perhaps  especially,  if  stations  happen 
to  be  located  at  such  points;  and  it  has  seemed  better  to 
put  in  escalators  or  elevators  than  to  drop  the  track  grade 
down,  involving  braking  on  a  descending  grade  and  accel- 
eration against  an  opposing  grade. 

In  one  instance  at  least,  on  the  original  subway  (at  33d 
St.  and  Park  Ave.)  on  the  four-track  section,  the  two 
center  tracks,  which  are  used  for  the  expresses,  are  carried 
through  on  an  even  grade,  while  the  outer  two  local  tracks 
are  raised  up  at  the  station.  On  the  new  lines  the  tracks 
generally  all  follow  the  same  grade  except  on  Lexington 
Ave.,  where  the  express  tracks  are  located  on  a  lower 
grade  in  the  tunnel  through  the  hill ;  but  here,  on  account 
of  the  necessity  of  having  an  express  stop  at  somi1  point  as 
nearly  as  possible  midway  between  42d  St.  and  125th  St., 
it  was  necessary  to  bring  the  express  tracks  up  near  the 
surface  at  86th  St.,  as  shown  in  the  profile,  Fig.  7,  which 
is  very  typical  of  the  way  local  conditions  absolutely  con- 
trol the  profile.  From  an  operating  standpoint,  of  course, 
it  would  have  been  much  better  to  have  run  all  the  way 
through  the  hill  on  the  lower  grade. 

On  account  of  the  capacity  of  the  electric  motor  for 
overload  also,  there  is  little  necessity  for,  or  benefit  to  be 


ff 

BH  '  r 

\ 

^. 
* 

| 

I 

lt|J           §..„....-., 

-. 

*> 

Y 

V                                       V 

I 

» 

Taf 

•u"8 

V 

f       *  —  T? 

$                            '•> 

V 

5 

K 

Kb 

. 

GJ 

K—  -  67L0  Length  over  Buffers 


47-0"C.ioC.  of  Bolsters - - -(-— -\—. >J 


V   JENS. 


ENS.NEW6 


FIG.  9.     DESIGN  FOR  STEEL  CAR:  BROOKLYN  RAPID  TRANSIT  SYSTEM 


then  the  motors  are  designed  to  carry  the  load.  Momen- 
tum is  availed  of  wherever  possible,  where  under  normal 
conditions  trains  may  be  expected  to  utilize  it  in  overcom- 
ing ascending  gradients,  and  this  can  be  quite  safely  done, 
because  in  case  a  train  is  stopped  on  an  up  grade,  the 
motors  can  be  relied  on  to  start  it  and  move  it  along,  even 
though  at  low  speed,  on  account  of  their  great  capacity  for 
overload.  The  original  subway  equipment  was  designed 
on  a  basis  of  about  60%  motors  and  40%  trailers,  but  the 
tendency  is  toward  the  equipment  of  all  cars  with  motors. 
On  the  underground  lines  so  far  as  possible,  stations 
have  been  located  at  summits  of  gradients,  both  in  order 
to  get  them  as  near  the  surface  as  possible  and  also  that 
the  ascending  gradient  may  be  utilized  in  braking,  and  the 
descending  grade  to  help  acceleration.  While,  however, 
these  two  purposes  mutually  help  each  other  on  the  sub- 
way lines,  and  the  rise  and  fall  involved  is,  therefore,  not 
an  operating  expense,  this  is  not  the  case  on  the  elevated 
lines.  These  latter,  of  course,  must  maintain  a  certain 
minimum  elevation  over  summits,  but  the  comparatively 
slight  additional  cost  of  longer  columns  is  so  little  that 
there  is  every  inducement  to  avoid  dipping  down  into 


derived  from,  the  compensation  of  grades  for  curvature, 
although  it  is  not  uncommon  to  find  the  heavier  rates  of 
gradient  combined  with  quite  sharp  curvature,  as  for  in- 
stance, at  Vesey  St.  and  Broadway,  where  there  is  a  4% 
grade  on  a  curve  of  200  ft.  radius. 

By  reference  to  the  profile  of  the  original  subway  line 
(ENG.  XEWS,  Feb.  20,  1902)  it  will  be  seen  that  much 
steeper  gradients  have  been  found  necessary  on  the  new 
routes  than  are  used  on  the  present  line,  but  this,  as  is 
explained  above,  has  virtually  been  forced  by  the  condi- 
tions which  have  had  to  be  met,  which  are  more  onerous 
in  many  cases  on  the  new  routes  than  on  the  old. 

On  the  old  line,  the  Broadway  section  has  no  gradient 
in  excess  of  1.5%,  and  the  Bronx  branch  has  3%  grades 
only  at  the  crossing  of  the  Harlem  Eiver  and  2.2%  just 
beyond  where  the  line  comes  out  on  to  the  elevated  struc- 
ture. 

In  a  way  the  profile  given.  Fig.  7,  of  the  Lexington  Ave. 
line  from  40th  St.  to  <138th  St.  may  be  considered  fairly 
typical,  though  on  the  other  hand,  the  Varick  St.-Seventh 
Ave.  line  from  the  Battery  to  42d  St.  has  light  grades 


[18] 


throughout  its  length,  comparing  favorably  with  the  old 
line,  with  which  it  will  connect  at  42d  St. 

ALIGNMENT — The  alignment,  of  course,  is  governed 
by  the  same  considerations  of  the  necessity  of  following 
the  streets,  and  so  far  as  possible,  avoiding  encroachment 
on  private  property.  This  is  especially  difficult  in  the 
lower  part  of  Manhattan  where  the  streets  are  narrow  and 
crooked,  and  where  it  is  especially  difficult  to  turn  the 
curves,  so  that  in  some  instances,  notably  at  St.  Paul's 
Churchyard  at  Vescy  St.  and  Broadway,  and  also  at  42d 
St.  and  Lexington  Ave.,  it  has  been  necessan'  to  acquire 
easements  under  private  property  at  considerable  ex- 
pense. On  the  new  lines  all  stations  are  to  be  located  on 
tangents,  to  avoid  the  difficulties  found  on  the  original 
subways  with  stations  on  curves. 

On  the  present  subway  in  which  cars  51  ft.  long  and  9 
ft.  Qi/2  in.  wide  are  operated,  there  are  the  following 
sharp  cur 

Ft.  rad. 

City  Hall   loop 147Vi 

Forty-second  St.  and  Park   Ave 180 

South   Ferry   loop 191 

Main   express   tracks 225 

The  outer  rails  on  curves  were  elevated  for  speeds  of  30 
mi.  per  hr.  with  a  maximum  of  6^>  in.,  and  this  practice 
is  followed  in  designing  the  new  lines,  though  in  some 
cases  the  operating  company  has  increased  the  elevation 
in  the  old  subway  to  permit  speeds  of  40  mi.  per  hr.  on 
some  of  the  curves  of  large  radius. 

On  the  new  lines  500  ft.  has  been  considered  the  mini- 
mum radius  for  ordinary  cases,  200  ft.  the  absolute  min- 
imum, except  that  there  is  one  curve  of  150  ft.  radius. 
On  the  B.  R.  T.  lines  additional  clearance  has  to  be  pro- 
vided on  curves  to  provide  for  the  extra  overhang  of  the 
larger  cars,  67  ft.  long  and  10  ft.  wide,  which  that  com- 
pany proposes  to  use. 

Transition  curves  of  a  uniform  length  of  150  ft.,  irre- 
spective of  the  degree  of  curvature,  are  used  wherever  it 
is  possible  to  get  them  in.  Crandall's  formulas  and  tables 
are  used.  It  may  be  noted  that  curves  are  usually  laid  out 
with  radii  of  even  feet  instead  of  with  even  degrc^  - 
curvature. 

Coxxii.u  TS  AND  SPECIFICATIONS 

GENERAL  CLAUSES — The  clauses  of  the  specifications  in- 
dicating the  character  of  the  work  to  be  performed  under 
each  item  or  type  of  construction,  will  be  discussed  or 
quoted  under  each  separate  heading,  together  with  the 
descriptions  of  the  work.  The  general  clauses  of  the 
contract  and  specifications  where  they  differ  from  ordin- 
ary practice,  or  where  they  have  particular  applications  on 
this  work  are  briefly  noted  below. 

The  contracts  are  printed  in  pamphlet  form,  letter-size 
sheet  (8x11).  There  is  a  table  of  contents  at  the  be- 
ginning and  a  complete  index  at  the  end.  Plans  were 
published  originally  on  large  sheets  about  22x30,  litho- 
graphed and  bound  together,  but  this  has  been  changed 
for  smaller-sized  plans  which  are  lithographed  on  thin 
paper  uniformly  11  in.  wide,  and  bound  into  letter  sire 
(8x11)  pamphlets  the  same  as  the  contracts,  thus  mak- 
ing them  very  easy  and  convenient  to  handle. 

The  contracts  for  the  general  construction  do  not  in- 
clude any  station  finish  of  any  kind,  nor  the  track,  ballast. 
or  electrical  equipment  except  such  parts  as  necessarily 
have  to  be  incorporated  in  the  main  structure,  such  as 
conduits  for  electric  wiring,  power  cables,  etc.,  and  the 
ducts  or  pipes  for  lighting  wires  at  the  stations.  The 


automatic  pumps  at  the  pumping  stations  are  included 
as,  of  course,  the  drainage  has  to  be  taken  care  of  from  the 
beginning.  The  contract  drawings  usually  include  enough 
plans  showing  the  general  scheme  of  station  finish,  so  that 
the  contractor  may  have  this  as  a  guide  in  carrying  out 
his  work  and  that  he  may  make  due  allowances  for  it. 
All  necessary  changes  in  location  of  sewers,  water  and 
gas  pipes,  electrical  conduits,  etc.,  required  by  the  con- 
struction of  the  subway  are  included  in  the  contract.  The 
principal  changes  of  the  larger  structures  are  shown  on 
the  plans,  but  exact  details  of  smallei  pipes,  conduits,  etc., 
are  left  until  the  existing  pipes  are  uncovered  and  all 
subsurface  structures  definitely  and  exactly  located. 

Approximate  quantities  of  each  item  are  given  for  the 
purpose  of  comparing  the  bids  on  a  basis  of  total  cost. 
The  time  may  be  extended  or  diminished  if  there  is  anv 
material  change  in  total  quantities. 

There  are  provisions  calling  special  attention  to  the 
necessity  of  compliance  with  state  and  city  laws,  especially 
the  eight-hour  law  and  the  requirement  that  contractors 
shall  pay  the  union  scale  of  wages. 

As  the  work  is  to  a  large  extent  to  be  carried  out  in 
residential  districts,  there  are  provisions  which  give  the 
engineers  adequate  control  of  night  work  of  any  kind 
which  might  disturb  people  living  near  the  line.  Blasting 
is  not  permitted  between  the  hours  of  11  p.m.  and  7  a.m. 
There  are  strict  provisions  (regular  city  ordinance)  for 
the  storage  of  explosives,  the  maximum  capacitv  in  any 
magazine  being  250  lb.,  and  in  most  of  them  not  over 
1  00  lb. 

BOXD — A  certified  check  for  a  stated  sum,  varying  from 
$10,000  to  $25,000,  according  to  the  size  of  the  contract, 
is  required  with  all  proposals  and  a  bond  of  a  stated  sum 
of  approximately  10%  of  the  amount  of  the  contract  from 
the  accepted  contractor,  15%  being  retained  from  the 
monthly  payments  up  to  a  total  of  about  10%  of  the 
amount  of  the  contract,  after  which  only  10%  is  deducted. 

TIME — The  following  clause  is  of  interest  in  the  pro- 
vision for  completion  within  the  specified  time : 

In    the    event    of    delay the    city 

shall  be  paid  damages  for  such  delay.  Inasmuch  as  the 
amount  of  such  damages  will  be  extremely  difficult  to  ascer- 
tain, especially  in  view  of  the  fact  that  the  railroad  herein 
contracted  for  is  only  a  part  of  a  complete  system,  the  re- 
mainder of  which  is  to  be  constructed  under  other  contracts, 
it  is  hereby  expressly  agreed  that  damages  shall  be  liqui- 
dated and  paid  by  reducing  the  price  to  be  paid  the  con- 
tractor as  follows: 

The  provision  then  is  for  the  retention  of  1%  of  the 
amount  due  for  the  work  done  in  the  first  month  after 
the  time  elapses,  2%  for  the  second  month,  and  so  on. 

The  following  "blanket"  clause  is  of  interest  in  connec- 
tion with  works  of  large  magnitude,  where  the  subsurface 
conditions  are  as  uncertain  as  they  may  be  in  a  city : 

The  specifications  and  contract  drawings  hereinafter  men- 
tioned and  taken  in  connection  with  the  other  provisions 
of  this  contract,  are  intended  by  the  Commission  to  be  full 
and  comprehensive,  and  to  show  all  the  work  required  to 
be  done.  But  in  a  work  of  this  magnitude  it  is  impossible 
either  in  advance  to  show  all  details,  or  precisely  to  forecast 
all  exigencies.  The  specifications  and  contract  drawings  are 
to  be  taken,  therefore,  as  indicating  the  amount  of  work,  its 
nature  and  the  method  of  construction  so  far  as  the  same  are 
now  distinctly  apprehended.  The  railroad  is  intended  to  be 
constructed  for  actual  use  and  operation  as  an  intraurban 
railroad  of  the  highest  class,  adapted  to  the  necessities  of 
the  people  of  New  York,  in  the  best  manner,  according  to  the 
best  rules  and  usages  of  railroad  construction,  and  in  the 
event  of  any  doubt  as  to  the  meaning  of  any  portion  or  por- 
tions of  the  specifications  or  contract  drawings,  or  of  the 
text  of  the  contract,  the  same  shall  be  interpreted  as  calling 


[19] 


for  the  best  construction,  both  as  to  materials  and  work- 
manship, capable  of  being  supplied  or  applied  under  the  then 
existing:  local  conditions.  All  the  clauses  of  the  specifica- 
tions, and  all  the  parts  of  the  contract  drawings  are,  there- 
fore, to  be  understood,  construed  and  interpreted  as  intend- 
ing to  produce  the  results  hereinbefore  stated. 

MONTHLY  ESTIMATES — The  engineer  shall  make  an  es- 
timate of  the  amount  and  value  of  the  work  done  as  in  his 
opinion  shall  be  just  and  fair,  but  shall  not  necessarily  be 
governed  by  the  unit  prices  contained  in  the  contractors' 
proposal,  and  provided  that  such  estimate  shall  be  with- 
held or  reduced  if  in  the  opinion  of  the  engineer  the  work 
is  not  proceeding  in  accordance  with  the  contract. 

An  allowance  is  made  for  structural  steel  delivered,  at 
the  rate  of  $40  per  ton. 

The  contracts,  provide  that  the  city  shall  make  payment 
on  estimates  within  30  days  after  a  certificate  is  issued 


by  the  commission.  As  a  matter  of  fact,  payments  are 
usually  made  within  30  days  of  the  end  of  the  month 
covered  by  each  estimate.  Final  payments  are  to  be  made 
90  days  after  the  filing  of  a  certificate  of  completion. 

SHAFTS  AND  OPENINGS — Plans  showing  the  location  of 
all  shafts,  plant  to  be  erected  in  the  streets,  supports  of 
street  decking,  openings  in  decking,  etc.,  must  be  sub- 
mitted to  the  engineers,  and  receive  their  approval  before 
work  is  commenced.  This,  of  course,  is  in  addition  to  the 
regular  permits  to  be  obtained  from  the  city. 

LIABILITY — The  contractor  admits  (under  the  form  of 
contract)  that  if  the  work  be  done  without  fault  or  negli- 
gence on  his  part  that  the  plans,  etc.,  do  not  involve  any 
danger  of  foundations,  walls,  or  other  parts  of  adjacent 
buildings,  etc. 


[20] 


LOADINGS — The  subway  and  elevated  structures  are  all 
designed  in  accordance  with  the  specifications  for  assumed 
loadings,  and  strengths  of  materials  and  methods  of  cal- 
culation, as  given  in  detail  in  a  paper  presented  to  the 
American  Society  of  Civil  Engineers  by  Henry  B.  Sea- 
man, formerly  Chief  Engineer  of  the  Public  Service  Com- 
mission, and  under  whose  direction  thev  were  worked  up 
(Trans.  Am.  Soc.  C.  E.,  Vol.  LXXY,  p.'  313).  The  prin- 
cipal provisions  governing  the  design  for  steel  structures 
are  given  below : 

The  railroad  trains  on  bridges  shall  be  estimated  as  re- 
quired by  specifications  of  railroad  company. 

Elevated  or  subway  trains  shall  be  estimated  as  a  con- 
tinuous load  of  2000  Ib.  (2k)  per  lineal  foot  of  each  track, 
or  a  single  local  concentration  of  two  adjacent  motor  trucks 
with  axle  loads  spaced  as  follows: 


o   o 


o   o 


'•  f'-x 10'- ><-5'->l 

Trolley  ears  shall  be  estimated  as  continuous  at  1500  Ib. 
per  lineal  foot  of  each  track,  or  as  a  local  concen- 
tration of  one  ash  car  with  axle  loads  spaced  as  follows: 
(Note,  the  ash  cars  are  special  cars  used  by  the  B.  R.  T.  for 
removing  ashes,  etc.) 

The  roadbed  for  trolley  cars  on  bridges  shall  be  assumed 
as  12  ft.  wide,  and  shall  be  capable  of  carrying  the  loads 
specified  for  roadway  of  bridges. 

The  roadway  load  for  bridges  shall  consist  of  a  uniform 
load  of  120  Ib.  per  sq.ft.  of  surface,  or  a  local  concentration 
of  40k  on  one  axle  with  a  wheel  gage  of  8  ft.  This  load  may 
be  assumed  to  cover  a  space  of  12  ft,  wide  by  40  ft.  long. 

The  roadway  load  over  subways  shall  consist  of  a  uni- 
form load  of  600  Ib.  per  sq.ft.  of  surface,  or  a  single  local 
•nncentration  of  200k  on  four  wheels,  12  ft.  between  axles  and 
s  ft.  gage.  These  concentrated  loads  shall  be  assumed  to 


O     O 


o   o  ; 


be  distributed  over  an  area  of  2x2  ft.  on  the  pavement  and 
thence  through  the  earth  at  a  slope  of  one-half  to  one.  Side- 
walks over  subways  shall  be  assumed  as  loaded  at  600  Ib.  per 
sq.ft. 

Footwalks  for  bridges  and  platforms  of  elevated  R.U. 
station  shall  be  estimated  as  loaded  at  100  Ib.  per  sq.ft.  of 
surface.  Subway  platforms  shall  be  estimated  as  loaded  at 
150  Ib.  per  sq.ft.  of  surface. 

IMPACT  —  Loads  due  to  trains  or  trolley  cars  shall  be  in- 
creased for  impact  in  accordance  with  the  following  for- 
mula: 

S    =    Increase  In  per  cent. 

L  =  Length,  in  feet  of  ap- 
plied loading  which 
produces  maximum 
stress  in  the  member. 
Not  to  exceed  1000  ft. 


Xo  increase  shall  be  made  for  impact  to  horizontal  load- 
ing (centrifugal  or  traction  forces.) 

Wind  —  Provision  shall  be  made  for  wind  pressure  act- 
ing in  either  direction,  horizontally,  of  30  Ib.  per  sq.ft. 

Traction  —  Provision  shall  be  made  for  the  sudden  starting 
or  stopping  of  a  train  500  ft.  in  length,  estimating  the  co- 
efficient of  sliding  friction  at  10%. 

Temperature  —  Provision  shall  be  made  on  bridges  for  a 
variation  in  temperature  at  120°  F.  (a  difference  of  40°  in  the 
temperature  of  the  chords  of  the  same  truss,  or  in  that  of 
adjacent  trusses  of  the  same  structure  shall  be  considered  in 
spans  of  more  than  300  ft. 


The  following  table  shows  the  unit  stresses  (1  k  = 
1000  Ib.)  allowed  for  steel  used  in  the  structure  taken 
in  conjunction  with  the  foregoing  loadings  : 

Steel 
Medium 

structural         Cast 
20k  16k 

1  20k  20k 

16.5k 


Nature  of  stress 
Tension  (Net) 
Compression.     (1  Diam.) 
Compression     (12  Diam.) 


(Grose)  ....................  J 

(Gross)  .................... 


Compression,  Columns 


I' 
1  +  8000r' 


20k 
30k 
15k 
30k 
0.75kd 


16k 


Bending  (Beams,  outer  fiber)  ................ 

Bending  (Pins,  Rivets  and  Bolts)  ..................... 

Shear  (Pins,  Rivets,  web)     (Net  sec.)  ................. 

Bearing  (Pins,  Rivets  and  Bolts)  ...................... 

Bearing  (Roller)  per  lineal  in.  ........................ 

1  =  Length  of  column,  in  inches. 

r  =  Least  radius  of  gyration  of  cross-section,  in  inches. 

d  =  Diameter  of  roller,  in  inches. 

•Note:  Compression  members  In  steel  and  iron  shall  not 
receive  greater  unit  stress  than  that  allowed  for  12  diam- 
eters. 

When  beams  and  girders  are  embedded  in  concrete,  the 
concrete  will  be  assumed  to  take  20%  of  the  loading. 

In  case  of  field  rivets  25%  excess  will  be  added  to  the 
number  of  rivets  required  as  above.  (When  machine-driven 
this  may  be  reduced  to  20%  excess.) 

PRELIMINARY  INVESTIGATION 

Extensive  borings,  both  wash  and  core,  were  taken  be- 
fore construction  to  determine  as  nearly  as  possible  the 
character  of  the  subsoil,  depth  to  rock,  etc.,  although  the 


FIG.  10.     HALF  SECTION  OF  B.  R.  T.  SUBWAY  ON  FOURTH 

AVE.,  BROOKLYN,  BUILT  IN  REINFORCED  CONCRETE 

WITH  PIPE  GALLEEY  UNDER  SIDEWALK 

latter  is  extremely  irregular.  All  existing  structures, 
both  above  and  below  ground,  were  located  as  well  as  pos- 
sible so  that  proper  provision  might  be  made  for  taking 
care  of  them,  though  the  actual  final  disposition  of  many 
of  the  small  pipes,  etc.,  was  not  determined  until  they 
were  all  uncovered  by  the  excavation  and  accurately 
located. 

GENERAL  DESIGN 

Speaking  generally,  the  present  designs  are  based  ou 
the  use  of  structural-steel  frames  with  concrete  jack 
arches  between.  The  use  of  reinforced  concrete  is  very 
limited.  It  seems  to  be  generally  considered  that  the 
use  of  the  structural-steel  frame  greatly  facilitates  the 
support  of  the  street  decking  during  construction,  because 
just  as  soon  as  a  bent  is  set  up  and  riveted,  the  load  may 
be  transferred  to  it. 

Under  the  requirement  that  the  street  surfaces  shall  be 
maintained  and  their  use  for  vehicular  and  other  traffic 


[21] 


be  uninterrupted,  it  is  generally  necessary,  on  account 
of  the  width  of  the  excavation,  to  carry  this  decking  on 
timber  supports,  which,  as  will  be  seen  later,  fill  up  a 
large  part  of  the  excavated  space.  The  construction  of 
reinforced-concrete  structures  under  these  conditions  is, 
therefore,  somewhat  difficult  and  liable  to  be  patchy,  but 
by  proper  care  in  arranging  the  timbering,  the  steel- 
t'ramed  bents  can  be  erected  easily. 

The  usual  members  employed  in  the  steel-frame  type  of 
construction  in  these  subways  are  small  enough  to  be 
easily  handled,  so  that  reinforced  concrete  has  little 
advantage  in  the  use  of  small  construction  units.  The 
ease  of  construction  of  the  steel-frame  structure  and 
advantages  of  support  more  than  outweigh  any  disad- 
vantage in  the  necessity  of  using  skilled  steel  erectors, 
as  against  the  supposed  ability  to  use  unskilled  labor 
for  reinforced  concrete,  even  though  the  form  work  for 
the  concrete  with  the  steel  structure  is  little  less  than 


*',:2' 


........  8-IOi"          ><  -------  <?-/<?" 


•6  C.I. Drain  Pipe 


3* 


wm^ 


Concrefe- 


-Ifly  Waterproofing 


FIG.  11.     B.  R.  T.  SUBWAY  ON  BROADWAY  AT  CANAL  ST., 
HEAVY  FLOOR  TO  RESIST  UPWARD  PRESSURE  OF 

it  would  be  for  ordinary  reinforced  concrete.  Fig.  10 
shows  the  reinforced-concrete  design  adopted  in  1908 
lor  the  4th  Ave.,  Brooklyn,  lines,  which,  however,  were 
built  mostly  in  open  cut. 

The  use  of  the  specially  rolled  "bulb"  angles,  used  on 

C.  V  &* 

•  . 


'op  of 
Hock 


grade  of  the  lower  level  is  40  ft.  below  M.  H.  W.  or 
normal  ground-water  level.  The  heavy  girders  and 
thick  concrete  floor  required  at  this  point  are  shown  in 
Fig.  11.  A  typical  floor  to  meet  conditions  below 
ground-water  level  is  shown  in  Fig.  15,  which  is  a 
cross-section  of  part  of  the  Lexington  Ave.  subwav, 
where  the  line  passes  over  what  seems  to  have  been 
an  old  swamp.  This  special  type  was  designed  prin- 
cipally for  the  purpose  of  carrying  the  structure  on 
the  soft  ground.  Just  north  of  this,  at  Lexington  Ave. 
and  128th  St.,  where  the  subgrade  is  considerably  be- 
low the  water  level,  a  typical  design  (Fig.  16)  of  rein- 
forced concrete,  for  resistance  to  water  pressure  in  rock, 
is  used. 

On  account  of  the  fact  that  the   Xew  York  rock,  a 
micaceous  gneiss,  is  well  known  to  present  difficulties  of 
support— that  is,  on  account  of  bad  seams,  etc.,  to  be 
•'heavy''  in  places — it  was  decided  to  use  a  reinforced-con- 
crete linmg  for  the  deep-level  tunnels 
under  Lexington  Ave.     It  was  found 
on  opening  up  the  work,  however,  that 
the   necessary   temporary   supports   of 
timber  made  this  type  of  construction 
difficult  to  execute  satisfactorily,  and  a 
change    was,    therefore,    made    to    the 
design   shown    in    Fig.    13.     This,    as 
will  be  seen,  permits  the  construction 
of  the  center  wall  and  the  haunches 
with  the  steel  columns  and  longitudi- 
nal  I-beams,   so   that  a  direct  center 
support  can  be  built  to  the  roof,  which 
is  generally  sufficient  for  the  support 
oi  the  overlying  rock  without  timbering  during  the  con- 
struction of  the  concrete  arches. 

The  unstable  character  of  the  rock  and  the  variation 
in  thickness  of  the  cover  involved  some  changes  in  the 
location  of  the  tunnel  portals,  making  it  necessary  to  shift 
them  back  in  almost  every  case  to  get  sufficient  depth 


ENG.NEWS 


5 


SHOWING  YKKY 
WATER 


Sec+ion   in    Earth 


HoVf   Sec-Hon    in    Roch 


FIG.  12.     REIXFORCED-CONCRETE  SUBWAY  ON  LEXING- 
TON AVE. 

(This  shows  the  upper  level.  The  tracks  on  the  lower  level 
are  in  tunnel  with  a  roof  of  two  arches  supported  on  a  center 
wall  and  the  sidewalls.) 

the  original  subway,  has  been  abandoned  and  only  stand- 
ard steel  shapes  are  used.  Usually  the  columns  rest 
directly  on  the  concrete,  as  shown  in  the  normal  sections, 
Fig.  8,  but  in  certain  places  I-beam  grillages  are  pro- 
vided. No  stone-block  footings  are  used.  Where  the 
ground  is  soft  or  where  water  pressure  exists,  specially 
designed  floors  are  necessary.  One  of  the  most  im- 
portant of  these  places  is  at  Canal  St.,  where  the  sub- 


riter  z&i&v 

t  \ 

•  s'—-  > 

jBase  cf_ 

•'• 
K 

—  j- 

FIG.  13.     ALTERNATIVE  DESIGN  FOR  CENTER  WALL  US- 
ING STRUCTURAL  STEEL  INSTEAD  OF 
REINFORCED  CONCRETE 

of  overlying  rock  cover.  This  contingency  is,  of  course, 
covered  by  the  provision  in  the  contract  for  slight  varia- 
tions in  total  quantities.  The  heavy  ground  on  some 
of  the  sections  on  Lexington  Ave.  necessitated  the  design 
of  considerably  heavier  steel  sections,  as  shown  in  Fig. 
17,  for  use  at  these  places. 


[22]. 


Further  notes  in  regard  to  the  construction  of  special 
sections,  such  as  the  Harlem  River  Tubes,  steel  and  rein- 
forced-concrete  elevated  sections,  etc.,  will  be  found  under 
their  respective  headings. 

CROSS-SECTIONS — During  the  early  days  of  the  Public 
Service  Commission  (190T-08),  there  was  considerable 
discussion  in  regard  to  the  desirable  dimensions  of  the 
cross-section  of  the  new  lines  proposed  at  that  time 


the  table  herewith  and  in  more  detail  in  the  typical  cross- 
sections  shown. 

In  Fig.  8  (of  the  previous  article)  is  shown  a  cross- 
section  of  the  7th  Ave.  line  of  the  Interborough,  which 
is  the  minimum  section  for  the  new  lines.  Figs.  12  and 
14  show  the  Lexington  Ave.  line,  which  is  to  be  oper- 
ated by  the  Interborough,  but  which  was  designed  before 
the  question  of  operation  was  definitely  decided.  Fig.  11 


Case  of  \ p 


VHr.  flpe 


FIG.  14.     DOUBLE-DECK  SUBWAY  ox  LEXINGTON    AVENUE  BUILT  WHOLLY  IN  TUNNEL 


Base  of 


as    extensions   and   further   developments   of   the    rapid 
transit   lines   then   in   operation.     It   was   not   thought 
advisable    to    conclude    further    operating    contracts    on 
the    basi>    of    those    made    for    the    original    subway, 
and  it  was  found  difficult  to  arrive  at  any  other  which 
was    agreeable   to   both    parties.     It    was    then    decided 
to  go  ahead  with  the  construction  of  the  4th  Avenue, 
Brooklyn,   line  and   Centre   St.  loop,  leaving  the  ques- 
tion of  operation  to  be  decided  later.     It  was  thought 
that  if  neither  the  Interborough  nor  the  B.  E.  T.  would 
meet   the  views  of  the  Commission  in  regard  to  terms 
of    operation,    a    third    party    might    be    found, 
and    as    there    then    seemed    to    be    a    possibility 
that    this    might   be   one   of   the   existing   steam 
railroad   lines,   it  was   decided  to   provide  clear- 
ance  for   standard    railroad   equipment   and   the 
'V-i.irns  of  these  two  sections  were  modified  ac- 
i-orilingly  to  provide  this.     As  all  doubt  in  regard 
to  the  future  operation  has  now.  however,  been 
eliminated,    it    has    not    been    thought    necessary 
in  the  design  of  the  new   lines  now  to  be  built 
to  provide  for  larger  equipment  than  it  is  known 
will  be  used,  and  the  clearances  decided  on  for 
the  new  lines  are  only  slightly  larger  than  those 
provided  in  the  present   suliway.  as  is  shown  in 


.-hows  the  cross-section  of  the  Broadway-59th  St.  route  of 
the  B.  R.  T.  The  following  table  shows  a  general  com- 
parison of  the  dimensions  of  the  original  subway  and 

those  since  adopted: 

Height  above 
top  of  rail  Width* 

Original  subway 12  ft.  4  in.  12  ft.  6  in. 

Fourth  Ave.,  Brooklyn,  and 

Centre   St.    loop 14  ft.  6  in.  14  ft.  0  in. 

New  subways: 

B.  R.   T 12ft.  8  in.         14  ft.  3  in.  &  13  ft.  6  in. 

Interborough     12  ft  3  in.         13  ft.  6  in.  &  13  ft.  0  In. 

*From    center   of  columns    between    tracks   to    face   of   side 
wall.      (Columns  about  8  In.) 

Note — These  are  dimensions  on  tangents  and  are  increased 
on  curves  to  provide  equivalent  clearance. 

Concrete 


•5-Z  - 


•  -':.-;  :- 


Base  of  Kn'l 


L,6uides 

zfe ''• 


FIG.  15. 


FLOOR  ON  SECTION  12  OF  I-BEAMS  AND  CON- 
CRETE 


[23] 


As  is  shown  on  the  various  cross-sections,  provision  is 
made  for  building  the  conduits  for  the  electric  wires,  in  a 
side-bench  wall  with  a  walk  on  the  top,  instead  of  plac- 
ing them  in  the  sidewalls,  as  in  the  old  subway. 

The  standard  track  spacing  for  four-track  subweys  final- 
ly adopted  is  as  follows,  from  the  center  line  of  the 
four  tracks  to  face  of  sidewalls: 


!NTERBOROU6Hk- 
' 


Center  line 


/Concrete 
1-Ph 


Side-wall 


press  stations  during  the  rush  hours.  Under  present  op- 
erating conditions,  the  spacing  of  trains  is  determined 
probably  as  much  by  the  length  of  station  stops  as  by 
ability  to  run  the  trains  more  closely  together  between 
stations.  It  is  probably  difficult  to  determine  the  exact 
economic  dimensions  of  a  car  which  will  hold  the  maxi- 
mum number  of  people  and  at  the  same  time  permit  the 
minimum  time  of  stopping.  As  has  already  been  pointed 
out,  the  B.  R.  T.  has  decided  to  use  a  larger  car,  but  the 
Interborough  will  probably  of  necessity  be  obliged  to 
continue  the  use  of  equipment  interchangeable  with  that 
now  in  use,  and  therefore  all  new  lines  which  are  to  be 


8?||^S£^^ 

^^^^^m^^^^^^;  ;«££  \  •••<£$ 


'  /  Rod,  K  a  -to  C.  '"Concrete  J 

ELMS.  NEWS  •*" 


•••    Y 


One  or  more  Layers  of  Brick  in  Mas-H^---^^.'-  l..H°"s,<?.^l?^.-^i.^\ 


FIG.  16.    LEXINGTON  AVE.  SUBWAY  AT  129TH  ST.     DOUBLE-DECK  STEEL-PEAME  CONSTRUCTION  WITH 

HEAVY  EEINFOECED-CONCEETE  FLOOE 


Cross-sectional  dimensions  of  other  rapid  transit 
subways  in  the  United  States  are  approximately  as  fol- 
lows, there  being  many  minor  variations: 

Height  above 
top  of  rail  Clear  width 

Boston,  Tremont  St.,  1898 13  ft.  10  in.  12ft. 

Boston,  Washington  St.,  1905..  .       14  ft.  5  in.  12  ft.  2  in. 

Cambridge,    1910    -    14  ft.  9  in.  12ft.  6  in.  (a) 

Philadelphia.   1907 14ft.  12ft. 

H.  &  M.,  6th  Ave.,  1908   12  ft.  10  in.  13  ft.  (b) 

Note  (a) — The  Cambridge  subway  is  large  enough  to  take 
standard  steam  railway  equipment;  the  tracks  are  12  ft.  on 
centers. 

Note   (b) — Sidewalk   over  duct  bench  at  side. 

The  question  of  cross-section  is  one  of  considerable  im- 
portance. It  is  determined  largely  by  the  size  of  the 
cars,  the  economic  limit  of  which  is  controlled  largely 
by  the  time  necessary  to  load  and  unload  them  at  ex- 


used  exclusively  by  this  latter  company  are  designed 
on  that  basis,  only  very  slightly  larger  than  that  now 
in  use. 

The  cross-section  has  also,  of  course,  an  important 
bearing  on  the  question  of  ventilation ;  this,  however, 
is  discussed  more  fully  under  that  heading. 

On  some  of  the  routes  when  the  designs  were  made 
and  construction  started,  it  was  uncertain  whether  they 
were  to  be  operated  by  the  B.  R.  T.  or  the  Interborough ; 
Fig.  18,  for  an  adjustable  edge  to  the  platforms,  so  that 

either  the  9-ft.  Interborough  or  10-ft.  B.  R.  T.  cars 
could  be  used. 

TRACK  CONSTRUCTION — A  standard  track  construction 


[24] 


ha*  been  adopted  for  all  the  new  lines,  by  conference 
and  agreement  between  the  two  operating  companies 
and  the  Public  Service  Commission.  Rails  are  to  be  100 
lb.  opeuhearth  B  section  of  the  Am.  Ry.  Eng.  Assoc.  Ties, 
yellow  pine  6x8x8  untreated,  with  flat-bottom  shoulder  tie- 
plates  Ty2x9xy2  in-,  and  6-in.  cut  spikes.  In  the  subways 
trap-rock  ballast  y2  to  1  in.  will  be  used  as  a  cushion  over 
the  concrete  floor ;  as  the  head  room  is  limited,  there  will 
be  only  about  6  in.  of  ballast  under  the  ties.  Ample 
drainage  is  provided  by  drains  in  the  concrete  floor. 

Judging  by  experience  with  the  ties  in  use  on  the 
present  rapid  transit  lines  it  has  been  thought  that  treat- 
ment by  creosote  or  other  preservative  will  not  be  neces- 
sary. 

Guard  rails  are  to  be  used  on  all  curves  of  less  than 
2000  ft.  radius;  those  under  700  ft.  radius  will  also  have 

A 


Fit;.  IT. 


HEAVY  STEEL  SECTIONS  ix  CEXTEB  WALL, 
LEXIXGTOX  ATE.  LIXE  AT  59TH  ST. 


rail  braces  on  the  guard  rails,  as  well  as  for  the  outside 
rails.  Rolled  manganese  rails  are  to  be  used  practically 
entirely  for  all  frogs,  switches,  cross-overs,  etc.,  and  on 
all  curves  less  than  700  ft.  radius.  In  regard  to  the  neces- 
sity for  the  use  of  manganese  rails,  which  cost  about  2y2 
times  as  much  as  openhearth,  reference  may  be  made  to 
the  experience  of  the  Boston  Rapid  Transit  lines  (Exo. 
S.  Ot-t.  22.  ]!»08,  p.  458).  where  on  a  certain  curve 
l>essemer  rails  lasted  only  60  days. 
but  a  ca,<t  manganese  rail  had  shown 
(inly  about  y2  in.  wear  in  six  years. 
There  is,  of  course,  not  only  the 
wear  of  the  rail  to  be  considered,  but 
the  cost  of  changing  due  to  the  ab- 
normally high  cost  of  track  work 
under  the  extremely  heavy  traffic 
and  in  the  confined  space  in  the 
subways. 

At  stations,  in  order  to  facilitate 
cleanliness  and  sanitation,  a  special 
type  of  track  construction  similar  to  that  used  in  the 
Pennsylvania  terminal  station  in  Xew  York*  and  the 
Detroit  River  tunnels  t  is  to  be  used.  A  cross-section  is 
shown  in  Fig.  19. 

The  track  material  is  to  be  bought  by  the  Public  Service 
Commission  under  contracts  and  at  unit  prices  to  be  bid 
for  the  various  items  required;  it  is  to  be  stored  and  is- 
sued on  requisition  to  the  operating  companies  who  will 
install  the  track  as  part  of  the  "equipment." 


TBACK  LAYOUTS — The  arrangement  of  tracks  at  junc- 
tion points,  so  as  to  avoid  crossings  at  grade,  with  the 
consequent  delay,  as  well  as  danger,  has  been  the  subject 
of  considerable  thought  and  study.  In  the  present  sub- 
way there  are  three  junction  points,  at  Bowling  Green, 
City  Hall,  and  at  96th  St.  The  first  two  being  merely  junc- 
tions of  double-track  lines,  where  only  one  class  of  trains, 
either  local  or  express,  has  to  be  cared  for  on  each  route, 
did  not  present  any  particular  difficulty,  it  being  only 
necessary  to  depress  one  track  under  the  other  two.  At 
96th  St.,  however,  where  two  double-track  lines  come  to- 
gether into  a  four-track  section,  and  where  express  and 
local  trains  have  to  be  directed  from  any  one  line  to  any 
of  the  others  (in  the  same  direction),  the  problem  is 
more  complicated. 

The  present  layout  at  96th  St.  is  shown  diagrammatical- 
ly  at  D,  Fig.  20 ;  it  will  be  noted  that 
the  switches  and  slip  crossings  are  all 
on  the  north  side  of  the  station,  and 
that  as  trains  from  either  branch  mav 
and  do  continue  as  either  local  or 
express,  there  is  frequently  some  delay 
to  trains  before  they  can  approach  the 
crossings  to  enter  the  station  on  the 
proper  track.  This  would  not  lie  not- 
iceable on  lines  of  ordinary  traffic,  but 
under  the  conditions  existing  during 
the  morning  and  evening  rush  hours 
in  Xew  York,  the  slightest  delay  may 
be  magnified  into  a  serious  congestion 
of  the  whole  system. 

The  number  of  such  junction  points 
on  the  new  lines  has  been  consider- 
ably increased  and  typical  methods  of 
overcoming  the  difficulties  are  shown  in  the  three  dia- 
grams A,  B  and  C  of  Fig.  20. 

So  far  as  possible  in  all  the  designs  for  the  new  lines 
he  engineers  have  tried  to  avoid  any  slow  points,  such  as 
witches,  crossings,  etc.,  at  places  other  than  close  to  sta- 
tions where  trains  must  stop,  and  to  locate  them  on  the 
farther  side  rather  than  on  the  near  side  where  they 


Section  A-B 
Alternative  Design  of 
Center  Wall 


Detail  of  Platform  Edge 

FIG.  18.     DETAIL 

OF  ADJUSTABLE 

PLATFORM 

EDGE 


— -e-o-          - 


.     ..       —  -  ...i 

AV    Other 


Poin+s 


•"Trans.,"  Am.  Soc.  C.  E.,  Vol.  LXIX,  p.  305. 
f'Trans.,"  Am.   Soc.  C.  E.,  Vol.  LXXIV,  p.  349. 


FIG.  19.    TYPICAL  CKOSS-SECTIOXS  OF  TBACK 

would  be  reached  before  the  train  enters  the  station,  and 
where  in  case  the  line  is  not  clear  the  train  would  have  to 
make  a  signal  stop  before  reaching  the  switch  as  well  as 
the  station  stop  after. 

The  diagram  at  A  shows  the  track  layout  at  12oth  St. 
on  the  Lexington  Ave.  line.     It  will  be  noted  that  com- 


[25] 


ing  from  the  north,  trains  from  either  branch  reach  the 
station  without  crossing  any  switches,  are  both  on  the 
same  level  and  on  their  same  respective  sides  of  the  sta- 
tion. Continuing  south,  those  trains  which  become  ex- 


iiatb      ii9tb     izoth      KI*I 


S.B.L.  -6 —  S.B.W. 


Present   Subway 
96*  St.  Station 


Eastern  Parkway  8c   Utica   Ave 


The  DoMed  Lines  represent  depressed 
Tracks  beneath  -fhe  Tracks  shown  in 
Full  Lines 


/  Junction  at- 
MattAve.  8c  149* 
Station 


FIG.  20.     VARIOUS  TRACK  INTERSECTIONS 

presses  from  this  point,  pass  the  required  switches  within 
300  or  100  ft.,  while  the  locals  have  a  switch,  which  is, 
of  course,  a  slow  point,  at  119th  St.  (about  1500  ft.  be- 
yond the  station).  This,  however,  is  of  little  import- 
ance, so  far  as  causing  any  delay  in  the  south  bound  move- 


ment of  the  local  trains  is  concerned,  as  their  next  station 
stop  is  at  116th  St. 

Coming  from  the  south  the  expresses  reach  the  upper 
level  in  the  east  side  over  practically  a  straight  line  with 
no  switches,  with  just  enough  ascend- 
ing grade  to  slow  them  down.  Leav- 
ing, they  take  one  or  two  switches  as 
they  are  diverted  to  either  the  east 
or  west  branch,  but  both  within  300 
ft.  of  the  station.  The  locals  coming 
from  the  south  have  one  or  more 
switches  to  pass  before  they  reach  the 
station ;  this,  however,  is  not  of  impor- 
tance especially  as  they  do  not  any- 
where come  in  contact  with  the  ex- 
presses. As  may  be  seen  these  latter 
switches  are  not  necessary  for  the  opera- 
tion of  through  trains,  as  trains  from 
either  side  of  the  station  going  north 
reach  either  branch  without  crossing 
ENN&I;WS  the  tracks  of  trains  going  in  the  oppo- 

site   direction,    but    are    put    in    for 
convenience,  to  provide  two  extra  side 
tracks  for  any  emergencies  'of  opera- 
tion   at    this    junction. 

The  other  two  diagrams  are  self-explanatory,  except  to 
say  that  at  Eastern  Parkway  and  Utica  Ave.,  diagram  B, 
the  arrangement  is  not  quite  so  elaborate  as  there  is  not 
expected  to  be  such  heavy  travel  on  this  section. 


(Not  -tv  Scale  ) 


[26] 


e   and 


Ventilation 


Every  effort  has  been  made  to  so  design  the  new  sub- 
ways that  the  excessive  heating  which  occurs  at 
times  in  the  summer  in  the  present  subway  may  be 
avoided.  The  tracks  are  to  be  divided  so  that  trains  going 
in  one  direction  will  be  in  a  separate  tube  or  tunnel  from 
those  going  the  opposite  way ;  by  this  means  it  is  expected 
to  utilize  the  movements  of  the  trains  (the  so  called  pis- 
ton action  where  there  is  only  one  track  in  a  single  tube) 
to  push  the  air  ahead  and  out  through  the  openings  which 
are  provided  for  this  purpose. 

The  original  subway  is  completely  surrounded  by  an 
envelope  of  waterproofing,  and  it  has  been  thought  that 
this  has  prevented  the  dissipation  of  some  of  the  heat 
generated  by  the  motors,  brakes,  friction,  etc.,  into  the 
ground  surrounding  the  structure.  On  the  new  lines 
waterproofing  will  generally  only  be  used  where  actually 
necessary  to  keep  out  water,  that  is,  below  the  ground- 
water  line,  in  earth,  and  on  the  roof. 

Openings  in  the  roof  of  the  tunnel,  with  sidewalk 
gratings,  are  provided  over  the  station  platforms,  and 
generally  one  about  half  way  between  each  station  and 
one  at  each  end  of  the  stations  on  the  side  toward  the 
approaching  train,  these  latter  being  expected  to  take 
care  of  most  of  the  draft  caused  by  the  train,  instead 
of  allowing  it  to  create  a  current  at  the  platform  and 
up  the  stairways.  The  general  form  of  these  open- 
ings and  the  details  of  their  construction  are  shown 
in  Fig.  22,  and  a  typical  arrangement  of  location  in 
Fig.  21  (Tth  Ave.,  17th  to  24th  St.).  The  dimensions 
and  numbers  of  these  openings  have  been  so  fixed  that  it 
is  expected  that  the  current  of  air  coming  through  the 
gratings  in  the  sidewalk  will  be  barely  noticeable  to 
pedestrians. 

Fan  chambers,  which  are  all  arranged  so  that  they  may 
be  also  used  as  emergency  exits  to  the  streets,  are  pro- 
vided, one  about  midway  between  each  station.  They 
are  so  arranged  that  they  will  draw  the  air  from  the  tun- 
nel at  points  intermediate  between  the  stations  and  blow 
it  out  through  the  gratings  already  described,  thus,  of 
course  drawing  fresh  air  in  at  the  stations.  It  is  expected 
that  the  openings  alone  combined  with  the  action  of  the 
trains  will  ordinarily  provide  sufficient  ventilation,  the 
fans  being  used  only  occasionally  when  circumstances  re- 
quire. 

The  piston  action  of  the  trains  in  the  single-track  tube 
of  the  Hudson  &  Manhattan  R.R.  has  been  noticeably 
efficacious  in  promoting  efficient  ventilation,  but  except  on 
the  Fourth  Ave.,  Brooklyn,  line,  where  there  is  a  parked 
space  in  the  center  of  the  street  and  where  walls  are  pro- 
vided between  each  track,  it  was  not  considered  practicable 
to  divide  all  the  tracks  of  the  new  four-track  lines  so 
that  each  would  be  in  a  separate  tube,  on  account  of  the 
difficulty  of  providing  outlets  for  the  center  tracks.  It 
would  be  impractical,  of  course,  to  provide  openings  in  the 
roadway  of  the  streets,  and  in  order  that  the  openings  in 
the  sidewalks  might  be  used,  the  center  wall  only  was 
built  dividing  the  traffic  going  in  opposite  directions,  but 
leaving  the  two  tracks  on  one  side  in  the  one  space.  If 


this  does  not  produce  the  required  movement  of  the  air — 
that  is,  actual  propelling  movement,  not  mere  stirring  up 
as  in  the  present  subway — the  fans  must  be  utilized  to  sup- 
plement it.  Openings  about  2  ft.  wide  and  8  ft.  high  are 
provided  at  every  10  ft.  in  the  center  wall  as  a  means  of 
communication  between  the  two  sides,  and  as  refuge 
niches,  and  these  may  tend  to  reduce  the  piston  effect  to 
some  small  exent. 

Although  this  arrangement  in  the  four-track  section 
will  reduce  somewhat  the  positive  piston  action  of  the 
trains,  it  will  be  beneficial  to  the  extent  that  it  will  tend 
to  reduce  the  air  resistance,  which  has  been  shown*  to  be 
by  no  means  a  negligible  factor  in  cost  of  operation  in 
single-track  tubes,  though  this  cost  may  be  offset  by  the 
benefits  of  more  efficient  ventilation. 

The  actual  effect  of  all  these  different  items  and  of  the 
size  of  the  cross-section,  both  on  the  efficiency  of  ventila- 
tion as  well  as  the  cost  of  operation,  is  something  of  which 
little  is  actually  known,  but  in  view  of  the  enormous  ex- 
penditures which  are  being  made  and  which  undoubtedly 
will  continue  to  be  made  in  underground  railways  for 
rapid  transit,  in  subaqueous  tunnels,  etc.,  it  is  hoped  that 
further^experiments  along  the  lines  of  these  already  re- 
ferred to*  and  others  of  like  nature  may  be  continued. 

As  will  be  seen  by  the  diagrams,  the  object  of  the  design 
of  the  openings  has  been  to  provide  at  the  track  level  a 
space  into  which  the  air  pushed  ahead  of  the  train  may  ex- 
pand and  be  detained,  instead  of  being  pushed  by,  and 
then  provide  an  opening  above  through  which  it  may 
escape  to  the  surface,  there  being  apparently  little  reason 
to  doubt  the  efficacy  of  this  proposed  scheme. 
DRAINAGE  AND  WATERPBOOFING 

In  the  general  clauses  of  the  specifications  it  is  stated 
that  "it  is  the  very  essence  of  these  specifications  to  secure 
a  railroad  structure  underground  which  shall  be  free 
from  the  percolation  of  ground  or  outside  water.  The 
mixing  and  placing  of  the  concrete  and  the  placing  and 
protection  of  the  waterproofing  shall  be  with  this  end  in 
view. 

"In  general,  waterproofing  of  the  structure  will  be 
limited  to  the  roof  and  sidewalls  at  the  stations  and  over 
the  roof  between  stations,  and  to  those  surfaces  near 
ground  water  or  mean  high  water  if  ground-water  level 
is  found  for  any  reason  to  be  below  mean  high  water.  At 
other  places  free  drainage  shall  be  provided  by  pipe  drain, 
hollow  tile  or  broken  stone." 

The  specifications  provide  for  the  use  of  fabric  water- 
proofing, laid  in  hot  pitch  or  asphalt,  and  in  from  three 
to  six  thicknesses  or  plies,  and  for  brick  or  hollow  tile,  laid 
in  pitch  or  asphalt  mastic,  the  latter  to  contain  "one- 
third  pure  bitumen,  and  sand  and  cement  or  lime  dust  in 
proportions  governed  by  local  requirements  and  weather 
conditions." 

At  temperatures  of  50°  to  70°,  the  proportions  used  are 
usually  one-third  asphalt,  one-third  cement,  one-third 
sand:  in  colder  weather  the  proportion  of  asphalt  is  in- 


•J.  V.   Davies,   "Air  Resistance  in  Tube  Tunnels,'"'Trans..' 
Am.  Soc.  C.  E..  Vol.  LXXV,   1912. 


[27] 


creased  as  required  up  to  a  maximum  of  60%,  though 
50%  is  seldom  exceeded.  Lime  dust  is  apparently  not 
used  in  place  of  the  cement,  as.it  appears  to  require  a 
larger  proportion  of  asphalt  to  make  it  workable. 

The  fabric  waterproofing  is  generally  used  on  the  roof 
or  other  horizontal  surfaces  where  it  may  be  required, 
and  the  brick  in  mastic  on  the  sidewalls  or  on  any  vertical 


troweled    as    may 

perviousness. 


be    directed    In    order    to    add    to    Its    1m- 


Eeference  has  already  been  made  to  the  fact  that  on 
account  of  the  supposed  influence  of  the  waterproofing 
envelope  inclosing  the  present  subway,  in  retaining  the 
heat,  that  waterproofing  is  only  carried  out  in  the  new 
lines  where  the  evident  necessity  shows  the  need  of  pro- 


. :  Louvres 
:     I00<x4 


e** 


g,     C  Wx?V 

%         |     EN6.NEWS 


FIG.  21.    PLAN  OF  PORTION  OF  SEVENTH  AVE.  SUBWAY,  SHOWING  PROVISION  FOR  VENTILATION 


surfaces  and  under  the  floor  when  required  there.     At 
stations  brick  and  mastic  are  used  over  the  roof. 

In  the  concrete  specifications,  the  following  clauses 
apply  to  the  waterproofing  : 

The  proportions  of  cement  and  sand  and  stone  (or  gravel) 
used  In  making  protective  concrete  outside  of  waterproofing 
lines  on  sides  and  roof,  shall  be  as  follows:  1  part  of  cement, 
4  parts  of  sand  and  8  parts  of  stone. 


tection  to  keep  the  structure  reasonably  dry.  Much  great- 
er reliance  is  being  placed  on  the  provision  of  free 
drainage  to  take  care  of  small  quantities  of  water,  than 
has  been  done  heretofore,  this  being  in  line  with  recent 
experience. 

The  question  of  waterproofing  tunnels  is  comparatively 
modern  and  its  importance  is  due  principally  to  the  de- 


Buila'inyf  Line 


10-1?  ZSIb. 


EN6. 
NIWS 


Part-     Section      C~C 


Part-    Track     Floor     Plan 


FIG.  22.     PARTIAL  CROSS-SECTIONS  AND  PLANS  OF  DOUBLE-DECK  SUBWAY,  SHOWING  TYPICAL  ARRANGE- 
MENT OF  VENTILATING  OUTLETS 


Concrete  to  which  waterproofing  Is  to  be  applied  shall 
be  made  smooth  at  the  time  of  laying  and  shall  be  carefully 
protected  from  Injury  by  barricades  or  otherwise.  If  neces- 
sary until  thoroughly  set. 

It  Is  Intended  to  obtain  concrete  Impervious  to  water; 
the  concrete  shall  be  mixed  and  deposited  with  this  end  in 
view,  and  on  the  roof  of  the  railroad,  if  waterproofing  is  not 
used,  the  top  surface  of  the  concrete  shall  be  carefully 


velopment  of  electric  traction  and  of  the  numerous  un- 
derground lines  for  urban  rapid  transit.  On  that  sec- 
tion of  the  Pennsylvania  Railroad's  New  York  tunnels 
which  passes  under  the  Bergen  Hill*  on  the  Jersey  side 


•"The  Bergen  Hill  Tunnels  of  the  P.   R.R." 
Soc.   C.   B.,   Vol.   LXVIII,    p.    146. 


"Trans.,"  Am. 


[28} 


of  the  Hudson  River,  and  where  there  was  a  considerable 
seepage  of  ground  water,  the  ample  and  careful  provision 
of  free  drainage  without  the  general  use  of  waterproofing 
has  resulted  in  a  remarkably  dry  structure. 

On  all  the  new  subway  lines,  drain  pipes  are  laid  in 
the  floor  (under  the  center  of  each  track)  which  lead  to 
sumps  at  pump  chambers,  from  which  the  drainage  is  dis- 
charged by  automatic  electric  pumps  into  convenient 
sewers. 

These  floor  drains  have  grating  openings  in  the  con- 
crete floor  every  50  ft.  and  the  floor  grades  are  arranged 
(irrespective  of  the  track  grades)  so  that  there  is  a 
summit  between  each  grating  (in  the  case  of  steep  grades 
2  or  3%,  the  summit  is  just  below  the  grating) ;  4-in. 
pipes  lead  to  these  center  drains  from  the  sides,  and,  if 
necessary,  part  or  all  the  way  up,  to  take  care  of  any 
seepage  there  may  be.  In  the  case  of  the  Lexington 
Avenue  rock  tunnels,  these  side  drain  pipes  generally 
reach  up  to  the  bottom  of  the  loose  rock  packing  over  the 
roof.  See  Figs.  12  and  14. 

Speaking  generally,  there  are  two  typical  methods  of 
waterproofing.  The  first  where  the  structure  is  in  earth, 
where  the  water  level  (mean  high  water  or  ground  water) 
is  above  the  bottom  of  the  structure.  In  these  cases  the 
waterproofing  is  carried  across  the  bottom  and  up  the 

sides  to  about  2  ft. 
above  the  level  of  the 
water.  See  Fig.  15. 
This  drawing  also 
shows  the  waterproof- 
ing carried  over  the 
roof,  as  the  section  is 
taken  at  a  station. 

The  second  where 
the  structure  is  partly 
in  rock  and  where  the 
water  level  is  above  the 
rock.  In  these  cases 
the  waterproofing  is 
carried  from  a  point  2 
ft.  above  the  water 
level  to  the  rock  or 
more  commonly  sealed 
into  a  trench  in  the 
sand  wall,  as  shown  by 
the  sketch,  Fig.  23. 

When  the  water  lev- 
el is  below  the  top  of 
the  rock,  waterproof- 
ing is  not  generally  used  except  over  the  roof  (see  Fig. 
12),  and  in  the  case  of  the  Lexington  Ave.  tunnels,  even 
this  is  omitted. 

The  necessity  or  otherwise  of  using  the  waterproofing 
is.  of  course,  governed  entirely  by  the  local  subsurface 


FIG.  23.     EXAMPLE  OF  WATER- 
PROOFING   STRUCTURE    ix 
ROCK  WITH  BRICK  WALL 
LAID  IN  MASTIC 


conditions.  The  plans  provide  for  what  may  reasonably 
be  expected,  based  on  the  results  of  the  borings,  but  the 
judgment  of  the  field  engineers  is  relied  on  largely  to 
modify  this  to  conform  to  actual  conditions  developed 
as  the  work  progresses. 

In  that  section  of  Lexington  Ave.  south  of  100th 
St.,  where  the  structure  is  in  rock  tunnel  and  wholly 
above  the  water  level,  no  waterproofing  at  all  is  used; 
on  the  other  hand,  just  above  this  point,  at  about  102nd 
St.,  though  the  structure  is  wholly  in  rock,  the  water  level 
is  about  10  ft.  above  the  bottom  of  the  structure  and  the 
brick  in  mastic  is,  therefore,  carried  down  below  the 
floor  at  the  sides,  and  the  top  is  covered  with  1  ply  of 
fabric  and  two  layers  of  brick  in  mastic.  Burlap  coated 
with  an  asphalt  compound  is  generally  used  for  the 
fabric,  but  where  there  is  water,  as  in  the  bottom  under 
the  floor  or  in  depressed  bays,  etc.,  one  layer  of  felt  is 
used  first. 

At  stations  the  waterproofing  (3-ply  fabric  or  1-ply 
and  two  layers  of  brick  in  mastic)  is  carried  over  the  roof 
and  down  the  sides  to  below  the  track  level,  in  order  to 
prevent  any  damage  to  the  decorations,  as  well  as  to 
protect  the  offices  and  passengers. 

When  the  floor  is  to  be  waterproofed,  a  6-iii.  concrete 
base  is  laid  in  the  bottom  of  the  excavation,  and  two  lay- 
ers of  brick  laid  flat  in  mastic  laid  on  this;  at  the  sides, 
if  the  sheeting  is  to  be  left,  the  two  courses  of  brick 
in  mastic  are  generally  laid  right  against  it;  otherwise, 
where  the  sides  require  waterproofing,  the  steel  is  first 
erected,  then  a  hollow-tile  or  concrete-sand  wall  is  built 
behind  it,  on  which  the  waterproofing  fabric  is  hung 
and  then  the  concrete  sidewalls  are  built.  Loose  rock 
is  packed  behind  the  hollow  tile  as  it  is  built  up. 

In  many  cases  the  protection  wall  of  4-in.  hollow  tile, 
or  a  concrete  sand  wall  is  built,  then  the  steel  is  erected 
before  the  brick  in  mastic  is  laid  up.  The  steel  columns 
then  act  as  braces  for  the- rough  board  forms  necessary  to 
support  this  latter  until  the  mastic  hardens.  These  boards 
are  usually  painted  with  a  good  thick  coat  of  cement 
grout  to  prevent  their  sticking  to  the  mastic;  the  grout 
sticks  to  the  mastic  and  the  boards  are  easily  removed. 

An  inspection  of  the  various  bids  made  up  to  the  pres- 
ent time  shows  the  general  average  prices  for  the  above 
classes  of  work  on  the  contracts  awarded  to  be  approxi- 
mately as  follows: 


Waterproofing,  1  ply  per  sq.yd *0 

Waterproofing,  2  ply  per  sq.yd 

Waterproofing,  3  ply  per  sq.yd 

Waterproofing,  4  ply  per  sq.yd 

Waterproofing,  5  ply  per  sq.yd 

Waterproofing,  6  ply  per  sq.yd 1 

Brick  in  mastic,  per  cu.yd 27 

Vitrified  drain  pipes,  4  in.  per  lin.ft 5 

Vitrified  drain  pipes,  6  in.  per  lin.ft 

Vitrified  drain  pipes,  8  in.  per  lin.ft 

Vitrified  drain  pipes.  10  In.  per  lin.ft 

Vitrified  drain  pipes.  12  in.  per  lin.ft 

Cast-Iron  drain  pipes,  4  in.  per  Hn.ft * 

Cast-iron  drain  pipes,  6  in.  per  lin.ft 


50  to  JO. 60 
80  to  0.90 
1.20 
1.60 
1.76 
2.00 


10  to 

35  to 

55  to 

75   to 

00  to  30.00 

40 

50 

75 

90 

10 

75   to  $1.00 

00  to     1.26 


[29] 


p 


Electric 

Four-way  vitrified  ducts  with  round  holes  (3y2  in-) 
are  used  almost  entirely  for  electrical  conduits  in  the  sub- 
way; they  are  located  in  the  side  bench  walls,  as  shown 
in  the  various  cross-sections,  usually  a  double  tier  5  high, 
making  4.0  single  ducts. 

The  specifications  require  that  the  outside  dimensions 
(of  four-way  ducts)  be  not  less  than  9*4  in.  or  more  than 
10  in.  with  square  outer  lines  and  that  the  outside  walls 
and  webs  be  %  in.  thick. 

A  linked  mandrel  is  used  for  laying  and  the  joints  are 
wrapped  with  muslin  wraps  soaked  in  cement  grout.  The 
mandrel  is  arranged  so  that  the  back  part  of  it  holds  the 
joint  last  made,  while  the  forward  end  holds  the  joint 
being  made.  One  or  two  other  forms  of  wraps  have  been 
tried  but  with  little  success.  The  whole  bank  of  ducts  is 
usually  laid  up,  then  the  outer  face  of  concrete,  and  top 
of  the  bench  wall  put  in  place.  This  is  usually  done  be- 
fore rodding  to  insure  the  stability  of  the  duct  bank. 

Wherever  it  is  at  all  possible,  connections  are  made  from 
all  splicing  chambers  to  the  street,  so  that  cables  may 
be  placed  or  withdrawn  from  the  street  surface,  on  account 
of  the  difficulty  of  handling  them  in  the  subway  after 
operation  has  been  started.  Where  space  allows,  a  regular 
manhole  is  built  from  the  splicing  chamber  to  the  street 


.< 


pearance  of  the  drawing.  Fig.  30  shows  part  of  the  plan 
of  the  intersection  of  Prince  St.  and  Broadway  and  is 
fairly  typical  of  conditions  in  the  lower  part  of  the  city. 
It  would  seem  at  first  thought  that  certain  large  trunk 
sewers  and  other  important  subsurface  structures  might 
have  considerable  influence  on  the  location  of  the  rapid- 
transit  lines,  but  it  has  generally  been  found  easier  or  less 
costly  to  change  these  than  to  change  the  position  of  the 
subway.  This  latter,  of  course,  is  usually  located  as  near 
the  surface  as  possible,  and  any  change  would  mean  low- 
ering it,  which  would  be  undesirable  from  the  standpoint 
of  those  who  have  to  use  it,  and,  of  course,  would  mean 


C.I.  Manhole  Cover 


To  be  replaced 
by  I0"cab/e  feed  pipe     ft 
where  required  by    M 
local 'conai-fions  — — _.  p; 


•*m* 


55j 

Tl 

feZtfV/?' 


Brictfor 
'Concrete 


10  Cable 
FeedPipe 


k- 


PIG  24.     HORIZONTAL  SECTION  OF  SUBWAY  WALL  AT  CABLE  SPLICING  CHAMBER  AND  VERTICAL  SECTION 

THROUGH  MANHOLE 


surface,  but  where  this  is  not  possible  a  10-in.  feed  pipe 
is  built  in.  The  splicing  chambers  are,  of  course,  set  back 
and  project  outside  the  ordinary  cross-section,  a  typical 
form  being  shown  in  Fig.  24. 

The  prices  for  these  conduits  as  shown  by  contracts 
already  awarded  are  approximately  10  to  15c.  per  lin.ft. 
of  single  duct. 

EXISTING  UNDERGROUND  STRUCTURES 

The  construction  of  the  subway,  of  course,  necessitates 
many  changes  in  the  existing  underground  structures, 
such  as  sewers,  water  and  gas  pipes,  electric-wire  conduits, 
etc.  The  isometric  drawing,  Fig.  25,  shows  condi- 
tions at  Fulton  St.  and  Broadway  on  the  line  of  the  pres- 
ent subway  as  they  existed  24  years  ago.  Since  that  time 
very  great  additions  have  been  made  to  the  underground 
street  piping.  The  picture,  however,  gives  some  idea 
of  what  is  found  at  many  street  intersections,  though, 
as  a  matter  of  fact,  the  general  appearance  of  one 
of  these  cross  streets  in  the  down-town  section  is 
more  that  of  an  intricate  and  confused  jumble  of  pipes 
and  cables  of  all  descriptions  instead  of  the  orderly  ap- 


increased  excavation  with  proportionately  greater  expense, 
so  that  generally  speaking,  the  subway  is  located  regard- 
less of  any  of  these  structures  and  these  latter  moved  if 
necessary.  There  are  a  few  instances  where  it  has  not 
been  practical  to  move  some  of  the  large  trunk  sewers,  and 
these  will  be  noted  further  on. 

This  work  connected  with  the  changes,  etc.,  required  in 
the  existing  underground  structures  is  all  taken  care  of  by 
two  divisions,  each  covering  the  whole  city  in  its  own 
special  department.  One  under  C.  N".  Green  has  charge 
of  the  relocation  of  all  pipes,  conduits,  etc.,  and  the  other 
under  L.  D.  Fouquet  has  charge  of  all  the  sewer  re- 
location, design  and  reconstruction.  The  importance  of 
this  part  of  the  work  may  be  gathered  from  the  fact  that 
there  are  employed  in  these  two  departments  alone,  taking 
care  of  work  in  a  way  entirely  outside  of  the  main  con- 
struction, some  150  engineering  assistants,  the  changes  in 
the  sewers  alone  involving  an  expenditure  of  $6,000.000 
to  $7,000,000  and  the  construction  of  some  60  miles  of 
new  sewers. 

GAS  MAINS — One  of  the  most  important  developments 
in  taking  care  of  the  pipes,  etc.,  on  the  new  work  has  been 


[30] 


the  bypassing  of  all  the  gas  mains — that  is,  the  construc- 
tion of  new  pipes  for  gas — on  the  surface  of  the  street  and 
the  stoppage  of  the  flow  in  the  pipes  underneath  before 
commencing  the  excavation.  This,  of  course,  involves  also 
iiew  temporary  house  connections  as  well,  but  the  danger 
of  the  accumulation  of  gas  underneath  the  decking  is 
thereby  eliminated.  The  very  great  danger  from  this 
source  was  demonstrated  by  the  recent  explosions  at  23rd 
St.  and  5th  Ave.  (ENG.  NEVIS,  Mar.  12,  1914),  which 
while  generally  attributed  by  the  public  press  to  the  sub- 
way construction,  were  caused  if  at  all  only  very  indirectly 
by  this  work.  The  following  description  of  the  method 
of  dealing  with  the  gas  mains  is  contributed  by  C.  N. 
Green : 

"The  present  specifications  for  subway  construction  call 
for  the  street  to  be  planked  or  decked  over  in  the  business 


A  temporary  system  of  wrought-iron  pipes  or  bypasses  for 
gas  distribution  is  laid  in  the  gutters  and  connected  with 
the  live  mains  in  the  transverse  streets  and  the  house  and 
street-lamp  services  are  transferred  from  the  cast-iron 
mains  below  the  street  surface  to  the  temporary  system. 
There  is  then  no  live  main  or  pipe  containing  gas  below 
the  street  surface."  (Figs.  26  to  29.) 

"An  8-in.  gas  pipe  broken  off  in  the  excavation  might, 
under  existing  conditions,  deliver  1000  cu.ft.  of  gas  per 
minute.  A  10%  mixture  of  gas  and  air  will  perhaps  not 
always  produce  a  maximum  explosive  effect,  but  this  is 
assumed  for  convenience  and  is  very  near  a  maximum. 
This  would  make  10,000  cu.ft.  of  explosive  mixture  per 
minute.  A  subway  cut  25  ft.  deep,  60  ft.  wide,  would 
contain  390,000  cu.ft.  in  a  city  block,  so  that  theoretically 
in  39  minutes  the  block  would  be  filled  with  an  explosive 


Vault 
nPneuinatic  Tube 

Boxen 

18  Steam  Ccffl  Conduit* 
19  Steam  Oil  Valve  Vault. 
20  Steam  Go's  Trap  Vault  . 


Va.utt. 
Z3Steajn  Cat  Seturn  Pipe* 


4  £°xe«. 

34  CeUar  v,u;t» 
ZS  Horse 


JZIIf 

Vaults     ',- 


1  ft»  Ma..- 

2  Can  Stop  Oock 

3  1V«r 

- 
7  H«o«iv:r^  Baxinn 

8    Receiving  B.,  »  II 

e         C> 


25 


ENG.NEWS 


FIG.  25.     ISOMETRIC  VIEW  OF  UNDERGROUND  PIPING  AT  THE  INTERSECTION  or  BROADWAY  AND  FULTON  ST.  IN 

1890 


sections  or  where  traffic  is  heav}',  so  that  business  may  be 
carried  on  as  usual  and  with  as  little  inconvenience  to  the 
public  as  possible.  This  decking  then  forms  a  temporary 
street  surface  under  which  the  excavation  is  carried  on. 
In  time  dirt  and  the  sweeping  of  the  street  make  the  deck- 
ing tight  and  prevent  a  circulation  of  air  that  would  free 
the  excavation  of  gas  if  a  main  should  leak. 

"Cast  iron  is  used  for  gas  and  water  mains  when  they 
are  laid  underground  for  the  reason  that  it  lasts  much 
longer  under  such  conditions  than  wrought  iron.  It  is 
difficult,  however,  to  keep  the  lead-calked  joints  of  such 
pipe  tight  even  when  they  are  undisturbed,  but  when  they 
are  moved  in  excavating  and  hung  up  on  the  timbering, 
some  joints  are  sure  to  be  strained  and  begin  to  leak. 

"All  gas  mains  are,  therefore,  'killed'  where  they  would 
be  underneath  a  closely  decked  street,  except  in  rare  cases 
where  small  transverse  cast-iron  mains  are  replaced  under 
the  decking  by  wrought-iron  pipes  with  screw  connections. 


mixture.  This,  of  course,  would  not  be  absolutely  true 
as  the  gas  would  not  diffuse  itself  with  such  rapidity  and 
the  mixutre  would  be  higher  in  gas  near  the  break  in  the 
main  and  perhaps  be  too  low  in  gas  at  the  farthest  point 
to  explode.  If  the  mixture  should  explode,  however,  the 
gas  would  burn  where  there  is  an  excess  and  probably  set 
fire  to  the  timber  with  results  as  disastrous  as  the  explo- 
sion itself. 

"Gas  mixed  with  air  forms  a  very  explosive  compound 
which  only  needs  a  spark  to  ignite  it.  This  spark  might 
be  furnished  by  the  underground  trolley  of  the  surface 
railway,  by  one  of  the  numerous  cables  exposed  during 
the  excavation,  by  a  lighted  match  thrown  away,  by  fire 
engines,  by  the  shoe  of  a  horse,  or  by  blasting,  etc.  The 
violence  of  such  explosions  has  been  frequently  shown 
when  manhole  heads  have  been  blown  into  the  air,  and 
by  numerous  sewer  explosions  which  have  occurred  in  the 
last  few  years.  Philadelphia  and  Boston  had  examples 


[31} 


in  the  construction  of  their  subways  and  various  minor 
instances  have  attested  to  the  power  of  such  a  mixture. 
"Knowing  the  danger  from  gas,  both  the  gas  company 
and  the  engineers  of  the  Public  Service  Commission  have 
taken  every  precaution  to  avert  it.  It  was,  therefore,  de- 
cided not  to  leave  any  cast-iron  mains,  carrying  gas, 
under  the  decking  unless  properly  ventilated  by  means  of 
gratings  or  protected  by  watchmen.  Where  mains  cross- 
ing the  subway  excavation  could  not  be  cut  out  of  service 
temporarily,  wrought-iron  pipe  bypasses  were  to  be  built 


Commission  could  be  maintained.  The  pressures  were 
taken  continuously  for  several  days  and  if  these  readings 
were  satisfactory  the  longitudinal  mains  were  cut  off  and 
capped  at  intervals  of  two  blocks.  In  the  meantime  the 
bypass  pipes  were  laid  in  the  gutter  and  connected  up. 
These  were  6,  8,  10  or  12  in.  in  diameter,  depending  on 
the  requirements  of  the  different  districts.  Depending 
on  conditions,  one  or  two  lengths  of  pipe  were  used  to 


FIG.  26.    A  TEMPORARY  GAS  MAIN  RUN  NEXT  THE 
STREET  CURB 

over  the  street  or  in  the  case  of  small  pipes  carried  across 
under  the  decking.  All  connections  between  the  cast- 
iron  mains  and  the  wrought-iron  bypasses  were  to  be  car- 
ried far  enough  back  into  solid  earth  to  avoid  the  danger 
of  breaking  off  the  pipe  if  a  slide  or  cave-in  should  occur. 
"In  mains  to  be  'killed,'  the  flow  of  gas  was  first  stopped 
by  inserting  bags  in  the  pipe  and  readings  were  taken 
to  see  if  the  pressure  prescribed  by  the  Public  Service 


FIG.  27.     OVERHEAD  GAS  MAIN  AT  LEXINGTON 
AVE.  AND  112TH  ST. 

carry  back  in  the  transverse  street  and  the  turn  at  the 
curb  was  made  with  a  pipe  bent  to  fit  the  radius  of  the 
curb  corner,  Fig.  26.  The  pipes  in  each  transverse  street 
were  then  cut  and  capped  about  10  ft.  back  of  the  sheet- 
ing line  on  both  sides  of  the  proposed  excavation.  Con- 
nection was  then  made  with  the  largest  pipe  underground 
on  each  side  of  the  street  and  the  bypass  continued  under- 
ground across  the  transverse  street. 


iFiG.  28.     OVERHEAD  GAS  MAIN  ON  LOWER  BROADWAY 

[32] 


"Generally  there  are  from  one  to  five  pipes  on  each  side 
of  the  transverse  streets.  Where  there  is  more  than  one 
pipe  on  the  same  side  of  the  street,  each  is  connected  back 
of  the  caps  with  a  1^-in.  circulation  connection,  the  ver- 
tical legs  of  which  are  tapped  into  the  top  of  the  pipe. 

"'In  laying  the  first  bypasses  little  attention  was  paid 
to  the  necessity  of  keeping  the  tops  of  the  pipes  level 


igmpomry  Bypa&s 


Curb 


EN6. 
NEWS 


FIG.  29. 


TYPICAL  METHOD  OF  PLACING 
GAS  MAIN  AT  Cri?B 


with  or  below  the  curb.  As  a  consequence,  numerous  ac- 
cidents occurred,  due  to  persons  slipping  or  tripping 
over  the  pipe.  In  one  instance  where  the  pipe  did  not 
lie  close  to  the  curb,  a  boy's  leg  was  broken  by  being 
caught  between  it  and  the  curb.  Now  all  pipes  are  laid 
close  to  the  curb,  with  the  top  not  higher  than  the 
curb  even  if  necessary  to  remove  the  gutter  stones,  and 
the  remaining  space  is  filled  with  concrete. 

"Extra  heavy  wrought-iron  pipe  has  been  used  gener- 
ally, so  that  when  the  bypasses  are  moved  the  pipe  can  be 
used  to  relay  the  cast-iron  mains  over  the  subway.  The 
gas  company  has  found  this  desirable,  as  the  vibration 
from  the  passing  trains  loosens  the  calking  in  cast-iron 
pipes.' 

"In  Tx>wer  Broadway  from  Canal  St.  south  are  two 
mains  16  and  20  in.  in  diameter,  respectively,  supplying 
the  lower  part  of  the  city.  These  mains  were  bypassed 
during  the  building  of  the  subway  from  Vesey  St.  to 
Canal  St.  Wrought-iron  pipes  with  flanged  connections 
were  laid  about  14  ft.  above  the  sidewalk.  The  trestle 
bents  were  so  placed  as  to  avoid  entrances  and  interfere 
with  business  as  little  as  possible.  At  cross  streets  where 
trestle  bents  could  not  be  erected,  the  pipe  was  trussed 
with  wire  rope  anchored  to  the  pipe  with  clamps. 

"In  138th  St.  are  one  16-in.,  one  20-in.  and  one  24-in. 
gas  mains  forming  a  crosstown  connection  between  the 
uorks  and  the  lower  west  side  of  the  Bronx.  As  these 
were  within  the  sheeting  lines,  they  were  killed,  and  to 
take  their  place  two  24-in.  riveted  steel  pipes  were  laid 
en  trestles,  one  on  each  side  of  the  street. 

"In  various  locations  are  large  feeder  or  pumping 
mains  crossing  the  line  of  the  subway,  and  these  main? 
generally  were  bypassed  overhead,  giving  about  14  ft. 
clearance  for  the  street  cars  and  other  vehicles.  A  de- 
scription of  one  would  be  typical  of  all.  Fig.  27  shows 
the  bypass  for  the  36-in.  main  crossing  Lexington  Ave. 
at  112th  St.  The  bypass  pipe  is  a  30-in.  wrought-iron 
riveted  pipe  carried  on  two  gallows-frame  supports  back 
of  the  building  line  in  the  side  street.  Between  these 
frames  the  pipe  is  suspended  from  two  wire  ropes  car- 
ried over  the  gallows  frames  and  each  anchored  back  to 
a  deadman.  The  deadman  consisted  of  an  inclined  I- 
beam  carried  well  below  the  street  surface  and  its  lower 
end  embedded  in  a  block  of  concrete.  The  main  in  the 
street  was  bagged  off,  the  pipe  cut  and  a  three-way  and 
valve  inserted  in  the  line  of  the  pipe.  This  operation 
was  repeated  on  the  other  side  of  Lexington  Ave.  The 
bypass  was  then  connected  to  the  three-ways  on  either 
side  of  the  avenue,  the  bags  removed  and  the  valve 


Section    A-B     (Enlarged) 

FIG;  30.    A  TYPICAL  REARRANGEMENT  OF  UNDERGROUND 
PIPING  AT  A  STREET  INTERSECTION,  OLD  AND 
PLANS  OF  UNDERGROUND  PIPING  AT  BROAD- 
WAY AND  PRINCE  ST. 


[33] 


closed  to  throw  the  gas  into  the  bypass  and  kill  the  main  on  local  conditions.     The  average  cost,  however,  should 

underground.  be  about  $2500. 

"The  cost  of  bypassing  service  mains,  using  6-  or  8-in.         "After  the  construction  of  the  subway  and  the  restora- 

wrought-iron  pipe  laid  in  the  gutter,  varies  but  little  tion  of  the  underground  pipe,  the  bypasses  are  removed 

from  $50,000  per  mile  of  street  bypassed.     The  distri-  and  the  street  restored  to  its  original  condition." 


;i:^o^^^p^^^h 

3CJI---J---_ji — il W--, ji a'xfg" 


New  9-3  Circular  Setver,  Grade  &I7% 


New  7-6xlOL3"Sewer.  Grade  0.17%  ^ 
£ 

h? 


New  9-3  Circular  Sewer.  6racte  0.17% 


New  6-6" Circular  Setver,  6rade  0.26% 


-100 


PROFILE  ALON6  30T-H  ST.  TO  SHOW  NEW  SEWER  BUILT  FROM  THE  UNDER-CROSS1N6   OF  THE  SUBWAY  TO  THE  HUDSON  RIVER 


PROFILE  SHOWIN6  DIVERSION  AND  RECONSTRUCTION  OF  SEWER   ON   7™  AYE.  AND   23?-D  TO  30^  STREET 


100 


7"°, 


'/fools,  6g"C.-hC. 


-4 


^^'>!:V7s>'?:J 


"tV"  '"  tV'"f*",'>»l'<ilc&»>t;lU>L:ri>L]>ir 

I  Firm   6rounc/J  (Soft  Grout-re/^ 


^.jv.",t.-i-"Sr^-.-/    -sj't-,""  ^'-r^W-i-^ 

3*'_1--?.:'.TH  ^vl^flSiltii-ii-i*-! 


DETAIL     OF    BAND 


TUNNEL     SECTION 
THROUGH    RCXK 

TYPICAL    CROSS -SECTIONS   ON   3QTI1  STREET 


, 
8'C.ioG. 

TWIN    SEWER    AT   \€^  AVE. 


FIG.  31.    TYPICAL  SEWER  KECONSTRUCTION  WORK  ON  30TH  ST.  AND  SEVENTH  AVE. 

bution  mains  requiring  16-  to  30-in.  bypasses  in  general  SEWERS — The  work  of  the  department  in  charge  of  the 

run  across  the  island  from  the  east  to  west,  thus  cross-  necessary  sewer  relocations  commences  as  soon  as  a  new 

ing  most  of  the  subway  lines  nearly  at  right  angles.   The  route  is  proposed,  as,  although  the  subways  are  generally 

cost  of  carrying  a  distribution  main  across  the  street  located  with  little  regard  for  existing  subsurface  struc- 

on  trestle  may  vary  from  $1000  to  $10,000,  depending  tures,  minor  changes  and  adjustments  in  elevations  and 

[34] 


gradients  are  quite  often  found  to  be  desirable.  General 
studies  of  the  sewer  situations  are,  therefore,  necessary 
from  the  beginning.  The  sewer  changes  are  worked  out 
in  consultation  with  the  city  authorities  and  the  plans 
are  made  part  of  the  contract  drawings.  This  same  de- 
partment makes  the  preliminary  studies,  final  plans  and 
supervises  construction. 

Generally  the  existing  sewer  line  is  located  in  the 
center  of  the  street.  The  construction  of  a  subway 
therefore  usually  involves  its  complete  elimination,  and 
the  substitution  of  two  lines,  one  on  either  side.  In 
Manhattan  also  the  main  trunk  sewers  and  intermediate 
main  lines  are  generally  located  in  the  cross  streets  run- 
ning east'  and  west  to  the  Hudson  or  East  Eiver.  The 
construction  of  a  subway  on  one  of  the  main  north 
and  south  avenues  therefore  cuts  these  all  off,  as 
they  are  nearly  always  located  below  the  level  of  the 
roof. 

On  what  may  be  referred  to  as  the  down  stream  side 
of  the  avenues  the  problem  is  usually  comparatively  sim- 
ple. A  new  line  is  laid  between  the  subway  and  the 


Generally  speaking,  however,  the  large  sewers  where 
they  have  been  encountered  have  been  passed  under  the 
subway  by  means  of  siphons,  and  while  this  is  not  gen- 
erally considered  desirable  for  sewers,  those  so  far  built 
seem  to  be  working  satisfactorily.  The  general  princi- 
ple on  which  they  are  designed  is  much  the  same  for 
all;  that  is,  a  comparatively  small  pipe  for  the  so  called 
"dry-weather"  flow,  with  one  or  two  larger  pipes  for 
the  storm  flow.  The  plan  and  section  shown,  Fig.  32, 
of  the  siphon  at  110th  St.  and  Lexington  Ave.  is  quite 
typical.  Most  of  the  siphons  have  been  built  with  easy 
slopes  for  the  drop  or  rise,  but  in  one  instance  in  Brook- 
lyn, at  Hudson  St.,  perpendicular  raises  were  required 
on  account  of  the  cramped  conditions.  In  this  case  a 
wide,  very  shallow  additional  safety  overflow  was  pro- 
vided over  the  roof  of  the  subway. 

Cross-sections  of  particular  forms  of  construction  not 
usually  met  with  in  sewer  work,  but  required  by  the 
exigencies  of  limited  clearance  in  many  cases  in  con- 
nection with  the  subways,  are  shown  in  Fig.  33.  An 
interesting  temporary  expedient  was  adopted  on  the 


INTAKE  CHAMBER 
t6ote 
/Chamber 


tut  \5eaJed Head 


P  1  00 
Street  Live/,  £1. 113. 10* 


Sealed  Head*': 


^'Bypass** 
OUTLET  CHAMBER     {* 
Eas+Gorte; 
Chamber. 


42  CJ.Pipe,  .. 
(Dry  Weather  Flow) 

EN6.NEW& 


6-6  Circular  5form  Pipe-*' 
Loingrrudincil  Section 


ffet'nf 
Goner.-,} 


FIG.  32.    INVERTED  SIPHON  CAEEYING  SEWER  UNDER  SUBWAY  AT  HOTH  ST. 


Section 
under  Subway 


buildings,  connecting  at  the  cross  streets  to  the  existing 
sewers,  which,  however,  of  course  only  get  part  of  their 
former  flow.  On  the  up  stream  side,  however,  not  only 
do  the  buildings  adjacent  to  the  subway  have  to  be  taken 
care  of,  but  also  the  flow  from  the  cross  drains  which 
have  been  cut  off.  The  least  important  of  these  cross 
sewers  are,  therefore,  collected  in  a  main  laid  parallel 
to  the  subway  and  carried  to  some  convenient  crossing 
point,  where  either  the  subway  can  be  lowered,  to  pass 
the  sewer  over  the  top,  or  where  topographical  condi- 
tions permit  the  sewer  to  go  under  and  continue  with 
sufficient  fall  to  the  point  of  discharge  into  the  river. 
The  conditions  at  30th  St.,  New  York,  are  quite  typical 
of  this  condition,  Fig.  31.  The  construction  of  this  one 
line,  giving  a  new  outlet  all  the  way  to  the  North  Kiver. 
cost  over  $500,000. 

In  a  very  few  instances  there  have  been  large  trunk 
sewers  which  could  not  be  changed  and  which  have  ne- 
cessitated a  very  considerable  adjustment  of  the  gradients 
of  the  subway  to  enable  the  line  to  pass  them.  At  Canal 
St.  and  Broadway  and  at  Duane  St.  and  West  Broadway, 
Manhattan,  the  subways  were  depressed  to  go  under  the 
sewer,  while  at  Brook  Ave.  and  138th  St.,  in  the  Bronx, 
the  surface  of  the  street  was  raised  5  ft.  to  enable  the 
subway  to  pass  over  the  top  of  the  sewer. 


Fourth  Ave.  subway  in  Brooklyn.  At  one  place  on  this 
line  it  was  necessary  to  take  care  of  quite  a  large  volume 
of  sewage  until  such  time  as  a  new  relief  trunk  sewer 
could  be  built  by  the  city.  The  subway  at  this  point 
was  built  for  six  tracks,  so  one  whole  bay  at  one  side 
for  a  length  of  2200  ft.  was  isolated  by  being  walled  in, 
waterproofed  and  turned  into  a  sewer  until  such  time 
as  the  relief  sewer  was  built. 

The  Duane  St.  sewer  in  Manhattan  is  typical  of  cer- 
tain conditions  which  have  to  be  met  and  where  advan- 
tage was  taken  of  the  peculiar  topography  of  New  York 
and  the  long  established  habit  of  drainage  into  the 
rivers  on  both  sides  of  the  city.  The  drainage  from 
Centre  St.,  through  which  the  so-called  Loop  line  runs 
from  Duane  to  Delancey,  was  to  the  East  River.  This 
was  cut  off  by  the  construction  of  the  Loop,  which 
was  too  deep  to  permit  the  construction  of  the  sewer  un- 
derneath, so  a  deep-level  sewer  was  built  under  the  original 
subway,  through  Duane  St.  to  the  North  River,  thus  re- 
versing the  flow  from  what  was  formerly  the  up-stream 
side  of  Centre  St.  It  is  this  new  sewer  that  the  Seventh 
Ave.  route  in  West  Broadway  has  to  go  under,  as  re- 
ferred to. 

The  numerous  questions  which  come  up  in  connection 
\rith  the  relocation  of  these  existing  underground  struc- 


[35] 


tures  are  only  hinted  at,  but  enough  is  given  to  show     work  and  the  skill  and  ingenuity  often  necessary  in  work- 
at  least  generally  the  importance  of  this  part  of  the      ing  this  out. 


Surface    of    S+reef 


(Note  Type   of  Tracfr^Cons+rucflonJ 


:5»Hfera.   <*&$. 

.  VfXOFV-~f-t\'S  -.WKV-WJ 

• 


New  6-6  Circular  Sewer,  Grade  O.Z5% 


CROSSING  UNDER  SUBWAY  AT  T^E1  AYE.  AND  SOTi1  STREET 


•Base  of  Rait 


'W~3-Hy     „  „ 
Waterproofing^^ 

Brick  in    '^ 
\Cern.  Morfar^t-- 


w& 

./.»-.-.'.°' 

>•':'•  •*:•'• 

•4/>.-? 


'..'•^•••V-i-.-.-tr--:'-^* 


up 

Jj^vJiV! 
?:?;',">;• 

r|"%*»JsJ 

s6"C.hC. 

•^  .<•:•'•:» 


:-?,^"%/<?f.jfeC 

''K'ffiSc. 

SECTION   UNDER   SUBWAY  AT  T1LLARY  STREET        SECTIONS  OF  STORM   SEWER  OVER  SUBWAY  AT  HUDSON  AYE.  AND 
AND  FLATBUSH  AYE.   BROOKLYN  FULTON    STREET,  BROOKLYN  ENS.  NEWS 


^7/7  /5r/77  Ear+h)  (in  ffoctr) 

SECTION   OF  TWIN  SEWER  UNDER  SUBWAY 


j^Iltl 

J?>  Ab£fc,IS~  "W 
4> 


(in  soft  6round) 
SECTION  OF  7-3"x  11-o"  SEWER 


fMasf/c 


•rpr: 


SEWER  CROSSING 
AT  DUANE  STREET 


SEWER  CROSS1NS 
AT  LEONARD  STREET 


FIG.  33.    TYPICAL  CROSS-SECTIONS  OK  FEW  SEWERS 


[36] 


fv^ a 

.ran 


The  specifications  for  the  construction  of  the  subways  in 
Manhattan  and  in  most  of  the  streets  in  Brooklyn  require 
that  the  work  be  "carried  on  under  covered  roadways." 
This  practically  means  that  the  paved  surface  of  the  street 
and  generally  also  of  the  sidewalks  has  to  be  taken  up  and 
replaced  by  a  timber  deck,  under  which  the  excavation 
and  construction  may  proceed  with  little  or  no  inter- 
ruption of  the  ordinary  street  traffic.  Openings  for  shafts 
to  give  access  to  the  excavations  are  permitted  at  inter- 


FIG.  34.     TYPICAL  TIMBER  DECKING  OVER  SUBWAY  EX- 
CAVATION, SHOWING  STRINGERS  SUPPORTING 
STREET  PLANKING 

vals  of  300  to  500  ft.  in  the  upper  part  of  the  city,  but 
are  about  1000  ft.  apart  in  the  lower  section. 

In  nearly  all  the  streets  in  Manhattan  where  the  sub- 
way >  are  being  or  are  to  be  built,  there  is  a  double-track 
street  railway  with  underground  contact  system  which 
lia-  in  \>e  supported.  In  Brooklyn,  the  Bronx  and  Queens, 
the  overhead  trolley  is  used,  which  makes  the  problem 
of  track  support  somewhat  easier,  though  of  course  the 
poles  have  to  be  taken  care  of. 

The  usual  method  of  procedure  is  first  to  excavate 
about  3  ft.  of  the  street  surface  on  one  side  of  the 


tracks,  putting  in  the  decking  and  track  supports  in 
the  form  shown  in  the  accompanying  views.  When  one 
side  of  the  street  is  decked  over,  the  other  side  is  taken  care 
of  in  the  same  way. 

Excavation  is  then  carried  on  under  this  decking,  the 
first  lift  being  from  10  to  15  ft.  in  depth,  practically  the 
depth  of  the  ordinary  cellars  and  basements,  the  walls  of 
which  usually  form  the  sides  of  the  excavation.  In  very 
wide  streets  the  full  width  is,  of  course,  not  taken  out, 
but  where  the  additional  width  beyond  the  neat  lines  is 
not  excessive,  the  whole  width  is  excavated  in  this  first 
lift,  as  this  permits  easy  access  to  the  buildings  for 
the  underpinning  operations.  Where  the  full  width  to 
the  cellar  or  vault  walls  at  the  sides  is  taken  out,  no 
sheeting  is  required  on  this  first  lift,  but  if  this  is  not  done 
sheeting  must  necessarily  be  driven  from  the  surface. 

Below  this  first  lift,  the  ordinary  form  of  timbering, 
using  rangers  and  braces  (see  Fig.  35),  may  be  contin- 
ued in  much  the  same  manner  as  for  the  excavation  of 
any  trench,  though,  of  course,  on  a  larger  scale,  or  one  of 
the  many  special  forms  hereinafter  described  and  illus- 
trated may  be  used.  There  are  two  general  types,  one  for 
earth  and  one  for  rock,  the  former  well  illustrated  on  the 
left  and  the  latter  on  the  right  in  Fig.  35  and  in  Fig.  38 
and  the  accompanying  drawings. 

The  essential  differences  are  the  necessity  in  earth  ex- 
cavation of  supporting  the  side  sheeting  as  well  as  the 
decking  and  in  rock  the  provision  of  a  clear  working 
space  and  to  guard  against  disaster  by  the  loosening  or 
destruction  of  one  or  more  supports  by  the  blasting  oper- 
ations or  by  slides  in  the  very  unstable  New  York  rock. 

One  of  the  most  interesting  of  the  methods  used  for 
support  in  a  deep  rock  excavation  is  that  developed  on 
Section  13,  Lexington  Ave.,  by  Messrs.  McMullen,  Snare 
&  Triest  and  illustrated  quite  clearly  in  the  photograph, 
Fig.  38,  and  the  sketch,  Fig.  39. 

On  this  section  the  concrete  troughs  which  support  the 
street-railway  tracks  are  first  supported  longitudinally 
by  the  three  or  more  6xl2-in.  timbers  laid  flat  (more 


FIG.  35.  TIMBERING  IN  EARTH  EXCAVATION  AT  LEFT  AND  ROAD  EXCAVATION  AT  RIGHT,  ON  LEXINGTON  AVE. 

[37] 


- '  FIG.  36.    STEEL  GIRDERS  ON  STREET  SURFACE  CARRYING  TIMBERING  AND  DECKING,  LEXINGTON  AVE., 

SECTION  11,  EOTTTE  5 


than  three  when  there  are  ducts  to  be  taken  care  of). 
These,  as  the  drawing,  Fig.  39,  shows,  are  held  up  by 
12xl2-in.  cross-beams  18  ft.  long,  which  are  blocked  up 
from  the  "needle  beams"  F,  which  are  12-in.  31^-lb. 
I-beams  30  ft.  long  spaced  10  ft.  apart.  It  may  be  noted 
that  it  was  not  usually  possible  to  put  these  needle  beams 
directly  tinder  the  blocking  of  the  troughs  of  the  street- 
railway  tracks,  on  account  of  the  presence  of  various  gas 
and  water  pipes,  etc.,  at  about  that  level,  a  condition 
which  obtains  quite  generally. 

These  needle  beams  have  two  pairs  of  6xl2-in.  yellow- 
pine  blocks  about  5  ft.  long  bolted  to  them,  one  on  each 
side  and  spaced  so  that  they  will  come  directly  under  the 
tracks,  as  shown  on  the  sketch.  These  wooden  blocks 
have  their  corners  cut  away  so  that  they  fit  tight  against 
the  web  and  under  the  flanges  of  the  I-beams,  making  at 
these  blocks  solid  points  of  support  for  the  longitudinal 
I-beam  stringers  underneath  or  for  any  temporary  block- 
ing or  posts  which  may  be  required,  and  tending  to  pre- 
vent any  overturning  of  the  needle  beam.  Long  X-braces 
and  turnbuckles  are  also  used  between  the  needles. 

At  the  end  of  the  needle  beam,  holes  are  drilled  so  that 
6xl2-in.  struts  to  the  sides  can  be  bolted  to  it,  the  6x1 2's 
being  fitted  tight  to  the  I-beam  the  same  as  the  needle 
blocking. 

The  needle  beams  are  then  supported  on  the  timber 
towers  shown  in  the  photograph,  Fig.  38,  by  two  pairs 
of  20-in.  65-lb.  I-beams  (A  in  Fig.  39),  which  are  bolted 
together  by  long  plates  to  develop  full  strength  at  the 
joints,  making  them  equivalent  to  a  continuous  beam  the 
whole  length  of  the  work.  On  either  side  of  these  two 
pairs  of  what  might  be  called  permanent  longitudinal  sup- 
ports, are  two  pairs  of  the  same  size  I-beams,  bolted  to- 
gether the  same  way,  the  outer  ones  C  80  ft.  long,  and 
the  inner  ones  B  120  ft.  long,  these  latter  being  used 
as  supports  from  the  last  timber  tower  over  the  face  of  the 
excavation  to  give  a  clear  span  of  50  to  60  ft.  over  the 
working  space. 

The  inside  120-ft.  pair  is  supported  on  the  tower  and 
on  blocking  just  back  of  the  working  face,  but  also  pro- 
jects back  of  the  tower  and  beyond  the  blocking,  and  these 
overhanging  portions  are  wedged  down  tight  from  the 
decking,  making  it  act  as  a  cantilever  (see  sketch,  Fig. 
39).  The  80-ft.  pair  spans  from  the  tower  to  blocking 
ahead  of  the  working  face. 

The  towers  are  spaced  40  ft.  c.  to  c.,  and  as  the  excava- 
tion progresses,  and  space  is  cleared  for  a  new  tower, 


these   pairs   of   I-beams   are   moved   ahead   for   another 
space. 

In  the  timbering  to  support  the  street  decking  and  the 
electric-car  tracks  the  plan  adopted  on  Section  9,  giving 
continuous  support  to  the  street-car  tracks  by  means  of 
I-beams  spliced  so  as  to  develop  full  strength,  is  worthy 


FIG.   37.     STREET   DECKING  AND   TIMBERING   CARRIED 

ON  HOLLOW  STEEL  PILES  UNDER  CHURCH 

ST.,  SECTION  1,  EOUTE  5 

of  note.  As  shown  in  Fig.  40,  there  are  three  pairs  of 
these  beams  directly  under  the  decking.  The  cross-tim- 
ber on  which  the  tracks  are  supported  is  suspended  from 
the  I-beams.  The  side  struts  or  diagonals  also  give  ad- 
ditional arching  support  so  that  the  danger  due  to  the  dis- 
placement of  any  of  the  posts  in  the  excavation  is  reduced 
to  a  minimum.  Fig.  40  shows  an  effective  method  of 
obtaining  clear  support  over  the  rock  excavation  for  the 
construction  of  the  lower-level  tracks. 

On  Sections  10  and  11,  after  some  trouble  with  slipping 
and  sliding  rock,  an  additional  means  of  supporting  the 
street  decking  was  adopted.  Continuous  girders  about 
4  ft.  high  and  150  to  200  ft.  long  were  erected  on  top 
of  the  decking  near  the  edge  of  the  sidewalk  and  the 
timbering  was  virtually  suspended  from  them,  as  is 


[38] 


shown  in  Fig.  41,  and  the  photograph,  Fig.  36.  These 
girders  were  generally  intended  to  be  supplementary  to 
the  system  of  supports  beneath  the  deck  and  to  be  neces- 
sary only  in  case  of  the  displacement  of  these  latter.  As 
a  matter  of  fact,  however,  they  proved  useful  in  spanning 


FIG.  38.     TOWEK  SYSTEM  OF  TIMBERING  IN*  ROCK 
EXCAVATION*,  LEXINGTON  AVE.,  SECTION*  13 

the  spaces  where  work  was  actually  being  carried  on  where 
changes  and  replacements  of  these  lower  supports  were 
frequently  necessary.  Their  disadvantage  is  that  they  oc- 
cupy  space  on  the  street  surface. 

Where  the  regular  system  of  cross-bracing  and  rangers 
are  required,  as  in  Section  14,  Lexington  Ave.  (McMul- 
len  &  Hoff  contractors),  where  there  is  earth  nearly  to 
subgrade,  some  very  elaborate  systems  of  timbering  are 
necessary.  The  type  of  timber  construction  on  this  sec- 
tion is  shown  in  the  photographs,  Fig.  35;  there  are 
seven  sets  of  braces  in  a  depth  of  about  40  ft.  below  the 


Conduits 

'  Xff.l2m.Heam  3/flk 
:F one 'every  /Off. 
i- rf. 

~ 


2,6'tir  fitted  and 
boffed  to  I-beam  to 
reach  fo  side  ofcxcavh 


A  a 


l2Off?O'-I-Seam 


M  M 


awanna  steel,  14-in.  arched-web,  41-lb.,  but  some  6-in. 
plank  (plain)  is  used.  The  steel  piling  mostly  showed  up 
quite  well,  although  there  were  numerous  boulders;  and, 
of  course,  in  some  places  where  they  were  struck,  the  pil- 
ing was  more  or  less  out  of  line  toward  the  bottom. 

On  this  section  careful  additional  horizontal  cross- 
bracing  was  carried  diagonally  from  the  center  at  each 
of  the  shafts  through  several  bents  to  the  sides,  which 
added  materially  to  the  rigidity  of  the  whole  structure. 

On  the  down-town  sections,  nearly  all  of  which  are  in 
earth,  more  or  less  similar  types  of  timbering  are  used. 
The  sides  are  necessarily  held  by  sheeting,  generally  wood, 
and  the  timbering  is  the  usual  system  of  rangers,  braces 
and  posts,  though  varied  in  detail  by  each  of  the  several 
contractors. 

The  street  decking  is,  of  course,  laid  first,  in  some 
cases  with  a  heavy  wearing  surface  of  6-in.  planks,  in 
others  2-in.  planks  on  closely  spaced  6x6-in.  timbers  or 
6-in.  I-beams.  The  first  lift  of  the  excavation  is  then 
taken  out  to  a  depth  of  10  or  15  ft.,  the  street-railway 
tracks  and  pipes  secured  and  generally  one  brace  is  car- 
ried across  the  whole  width  of  the  excavation,  this  first 
long  brace  being  usually  not  less  than  5  or  6  ft.  below  the 
surface.  Great  care,  of  course,  is  taken  in  all  these  sections 
to  arrange  the  timbers  so  that  they  will  clear  the  steel 
when  the  latter  is  erected. 

The  two  principal  variations  seem  to  be  in  making 
either  the  posts  or  the  braces  continuous.  On  Section  2, 
the  first  operation  was  to  sink  the  posts  in  sheeted  pits  to 
subgrade.  The  material  was  sand,  and  many  men  in 
New  York  now  have  become  quite  expert  in  sinking  these 
4x4-ft.  pits  in  soft  material  by  the  use  of  horizontal  sheet- 
ing (which  will  be  described  in  more  detail  under  the 
head  of  underpinning),  so  that  the  sinking  of  this  large 
number  of  pits  is  not  so  serious  an  operation  as  might 


Street  Surface 


Section  X~X 

A  -Continuous  teams  whole 

length  of  work 
0-  Continuous  beams  l?0ff.  long, 

moredafieadas  imr/roropresses 
C~'Continuous  beams  KW.iong, 
mewed  ahead  as  *ort  progresses 

FIG.  39.     SKETCH  SHOWING  STEEL  BEAM  SUPPORTS 

FOE  TRACKS  OVER  ROCK  EXCAVATION, 

LEXINGTON  AVE.,  SECTION*  13. 

deck  and  the  bents  are  about  10  ft.  apart.  Tension  rods 
are  put  in  to  help  hold  up  the  bottom  braces  during  ex- 
cavation. The  sheeting  on  this  section  is  mostly  Lack- 


FIG.  40.     TIMBERING  FOR  ROCK  EXCAVATION*  FOR  DOU- 
BLE-DECK SUBWAY,  LEXINGTON  AVE.,  BETWEEN 

78TH  AND  79TH  Si.,  SECTION*  9. 

be  imagined.  No  water,  of  moment,  was  encountered  on 
this  section  above  subgrade.  Once  the  posts  were  down,  of 
course,  the  deck  was  held  in  safety  for  any  operation  and 


the  continuance  of  the  excavation  and  timbering  was  a 
matter  of  routine. 

A  method  used  on  part  of  Section  3  is  clearly  shown 
in  Fig.  42,  which  needs  little  explanation.  The  building 
of  the  concrete  sidewall  was  not  followed  throughout 
the  section.  The  method  of  framing  the  timbers  to  get 


Sheathing 


-?SttelPls       *  It 
•1ft  Girder 
T.Lauers  nf  Decking 


These  bents.are  spaced 
about  10 'apart 


FIG.  41.    TIMBERING  SUPPORTED  FROM  LONGITUDINAL 

GIRDERS  ON  STREET  SURFACE,  LEXINGTON 

AVE.,  SECTION  10. 

an  arching  effect  is,  however,  to  be  noted,  as  this  prin- 
ciple was  applied  also  on  Section  1. 

The  features  of  this  system  as  developed  on  Section  1, 
by  J.  C.  Meem,  who  was  the  engineer  in  charge  for  the 
contractors,  are  the  combined  arching  and  bracing 
effect  secured  and  the  use  of  the  continuous  girder 
throughout  the  length  of  the  excavated  section,  supported 
on  posts  or  hollow  piles. 

At  a  convenient  distance  below  the  decking,  contin- 
uous 12xl2-in.  cross-braces  spanning  the  whole  width 
of  the  excavation  were  put  in,  10  ft.  apart.  These  were 
usually  made  up  of  two  6xl2-in.  timbers  bolted  together 
in  as  long  lengths  as  it  was  practical  to  use.  The  short 
12xl2-in.  cap,  with  the  ends  cut  as  shown,  was  then  placed 
under  the  cross-braces  and  supported  temporarily  while 
the  next  lift  of  5  or  8  ft.  was  excavated  to  the  level  of 
the  next  cross-brace. 

The  hollow-steel  piles  were  then  driven,  a  lOxlO-in. 
post  fitted  inside  of  them,  the  longitudinal  girders  ex- 
tended, and  the  arch  legs  and  posts  put  in  position.  The 
appearance  of  the  lowest  level  is  shown  in  Fig.  37. 

The  use  of  continuous  I-beams  for  the  support  of  the 
street  decking  or  for  tying  together  the  timbering  or  sup- 
ports is  a  feature  of  quite  a  number  of  the  sections,  dif- 
ferences in  detail,  of  course,  having  been  developed  by 
each  individual  contractor,  but  in  general  the  principle  is 
that  of  a  group  or  series  of  groups  of  I-beams  spliced  to- 
gether with  long  plates  to  obtain  100%  strength  at  the 
joints  and  running  the  whole  length  of  the  work  under 
the  decking  and  often  supporting  directly  the  street-oar 
tracks.  The  advantage  of  this  method,  of  course,  is  in 
its  general  security  in  case  of  accident  to  any  one  or  even 
more  of  the  supporting  columns  or  bents  and  also  to  per- 
mit easy  removal  or  change  of  supports  during  erection. 

An  interesting  and  unusual  example  of  the  method  of 
timbering  by  rangers  and  braces  applied  to  the  excavatioii 
of  a  large  area  in  water-bearing  material  is  that  of  Sec 
2-a  at  the  intersection  of  Broadway  and  Canal  St.. 


which,  on  account  of  its  difficulty,  was  let  as  a  separate 
contract.  A  double-deck  structure  is  being  provided  to 
permit  the  future  Canal  St.  cross-town  line  to  pass 
under  the  Broadway  line.  The  excavation  at  this  point 
is  some  55  to  60  ft.  deep  and  for  four-track  lines  approxi- 
mately 250  ft.  long  on  Broadway  and  150  ft.  on  Canal 
St.,  joined  by  a  connecting  curve  in  the  northeast  corner. 
The  extremely  heavy  floor  of  steel  girders  and  con- 
crete placed  in  the  bottom  of  this  section  to  resist  the 
water  pressure,  as  shown  in  Fig.  11.  will  convey  an  idea 
of  the  conditions  which  were  successfully  overcome. 

The  normal  water  level  on  this  section  is  about  15  ft. 
below  the  surface  of  the  street,  but  water  was  actually  not 
found  in  quantity  until  a  depth  of  about  23  ft.  was 
reached.  This  left,  however,  a  depth  of  30  ft.  to  be  exca- 
vated in  water-bearing  sand  and  gravel.  The  entire  area  is 
surrounded  by  buildings  and  there  is  a  very  heavy  travel  to 
support  on  both  streets,  so  that  it  was  necessary  to  exercise 
extreme  care  to  avoid  losing  ground. 

The  area  excavated  is  surrounded  by  6-in.  tongued-and- 
grooved  sheeting  driven  in  three  lifts,  and  great  care  was 
necessary  in  spacing  the  elaborate  system  of  cross-bracing 
to  permit  the  erection  of  the  steel.  There  is  nothing 
particularly  novel  in  the  layout  of  this  latter,  except 
its  great  extent  over  such  a  large  area;  special  care,  of 


12'Steel  Kk>S 

FIG.  42.     CONCRETE  SIDEWALLS  AND  ARCHED  TIMBER 

SUPPORTS  WITH  HOLLOW  STEEL  PILES  USED 

ON  BROADWAY,  SECTION  3,  ROUTE  5 

course,  being  necessary  to  keep  the  long  line  of  rangers  and 
braces  in  place  with  proper  cross-bracing,  and  to  so  de- 
sign the  whole  layout  that  the  steel  could  be  erected  with 
the  minimum  amount  of  interference  with  the  timbering. 
Fortunately,  the  large  amount  of  water  coming  into 
the  excavation  seems  to  be  quite  clear,  and  the  most  care- 
ful levels,  carried  out  for  a  considerable  distance  in  every 
direction  from  the  excavation  and  continually  checked, 
indicate  little,  if  any,  settlement  of  the  adjacent  ground  or 
buildings.  The  total  capacity  of  the  pumps'  is  about  20 
million  gallons  daily,  and  while  the  whole  capacity  has 
only  been  infrequently  required,  a  large  proportion  of  it 
has  been  needed  continuouslv. 


[40] 


The  general  specifications  provide  for  the  classification 
of  excavation  as  earth  and  rock,  rock  being  ledge  rock  in 
place  and  boulders  over  ^  yd.  Earth  excavation  is 
classified  as  above  or  below  mean  high  water,  and  the 
prices  "include  the  cost  of  the  disposal  of  the  materials 
excavated,  of  backfilling,  of  all  decking  and  bridging 
for  support  of  street  travel,  of  all  sheeting  and  bracing, 


FIG.  43.     DERRICK  FOR  HOISTING  SKIPS  AT  ??TH  Sr. 
AND  LEXINGTON  AVE. 

and  of  maintenance  and  supporting  of  trenches  during 
and  after  excavation,  of  all  pumping  or  bailing,  and  of  the 
maintenance  and  support,  with  all  incidental  work,  labor 
and  material  of  any  kind,  of  all  surface,  subsurface  and 
overhead  structures  and  surfaces."  (Support  of  street- 
railway  tracks  and  elevated  railroads  is  paid  for  sepa- 
rately as  noted  below.  Underpinning  of  buildings  when 
required  is  also  paid  for  separately.) 

Eock  excavation  is  paid  for,  for  6  in.  outside  the  neat 
line  at  the  sides,  but  no  allowance  is  made  on  the  bottom. 
It  is  required  that  all  excavation  in  rock  beyond  the  side 
neat  lines  of  the  structures  shall  be  refilled  solid  with 
concrete,  which,  except  for  the  first  6  in.,  is  at  the  expense 
of  the  contractor;  so  there  is  every  incentive  to  avoid  ex- 
cessive excavation  and  for  the  use  of  care  in  drilling  and 
blasting  at  the  sides. 

When  pipes,  sewers,  electric-wire  conduits,  etc.,  have 
to  be  removed  and  rebuilt  elsewhere,  the  work  is  paid  for 
separately.  All  structures  of  this  kind,  however,  which 
do  not  require  change  have  to  be  supported  and  main- 
tained by  the  contractor,  the  cost  being  included  in  the 
price  paid  for  excavation.  All  gas  pipes  are  removed  and 
placed  above  ground  during  construction,  and  replaced 
afterwards,  the  necessary  house  connections,  of  course, 
having  to  be  changed  each  time.  This  work  is  paid  for 
at  a  price  bid  per  linear  foot  for  each  size  of  pipe  which 
has  to  be  taken  care  of.  The  ordinary  4-  and  6-in.  pipes 
from  which  the  house  supplies  are  taken  are  usually 
relaid  along  the  edge  of  the  sidewalk,  on  top  of  the  tim- 
ber decking.  The  large  10-  and  12-in.  mains  are  usually 
supported  overhead. 

In  planning  the  excavation  it  has  generally  been  found 
advisable  to  so  arrange  the  work  that  if  the  material 
is  suitable  there  will  be  sufficient  left  till  the  end  to 
complete  or  nearly  complete  the  backfill,  which  the  speci- 
fications require  shall  be  made  with  "sand,  gravel  or 
other  good,  clean  earth,  free  from  perishable  material,  or 
stones  exceeding  6  in.  in  diameter,  and  not  containing 


in  any  place  a  proportion  of  stone  of  or  below  that  size 
exceeding  one  part  of  stone  to  five  parts  of  earth." 

Usually  there  is  no  opportunity  to  store  material  for 
this  purpose,  but  on  some  sections,  where  there  is  earth,  a 
certain  portion  at  the  ends  of  the  section  is  left  to  be 
excavated  after  most  of  the  structure  is  completed.  Where 
this  is  not  possible,  or  where  there  is  little  or  no  earth, 
dependence  is  usually  placed  on  material  excavated  else- 
where, mostly  from  cellars,  etc.,  of  which  there  is  usually 
sufficient  available  at  all  times  and  in  nearly  all  sections 
of  New  York.  In  one  case  the  contractor  was  able  to 
get  a  vacant  lot  for  disposal  of  his  earth  excavation,  con- 
veniently located  so  that  it  will  be  practical  to  remove 
the  material  (by  steam  shovel  and  train)  when  required 
and  use  it  for  backfill. 

The  following  table  will  give  a  general  idea  of  the 
range  of  prices  bid  for  excavation  under  the  many  vary- 
ing conditions: 

COST   PER   CUBIC   YARD   OF   EXCAVATION 


, Earth , 

Above  Below 
m.h.w.  rn.h.w.  Rock 
In  the  lower  part  of  Man- 
hattan  below   10th   ST...    J4.50  $7.00  J7.00 

to             to  to 

6.00          9.00  10.00 

From    10th    to    42d    St 400          ....  5.00 

to  to 

5.00  6.00 

:;  :."i          6.00  5.00 

to            to  to 

5.00          8.00  8.00 

Bronx     2.25          3.00  3.00 

to             to  to 

3.00          4.00  4.00 


/-—Sewers — 4 
Earth     Rock 


From  42d  to  125th  St.... 


$4.00 

to 
5.00 
4.00 

to 
5.00 
4.00 

to 
6.00 
2.00 

to 
3.00 


$6.00 


6.00 

6.00 

to 
8.00 
4.00 

to 
5.00 


The  cost  of  supporting  the  tracks  of  the  street  or  ele- 
vated railways  is  not  included  in  the  excavation  price. 


FIG.  44.     GANTBY  HOIST  FOB  SKIPS  AT  121ST  ST.  AND 
LEXINGTON  AVE. 

but  is  paid  for  separately.  The  prices  bid  on  the  contracts 
thus  far  awarded  range  approximately  as  follows: 

For  the  support  of  elevated-railway  columns,  from 
$300  to  $500  each,  though  in  one  case  where  there  were 
only  two,  the  bid  price  was  $1000  each. 

For  the  support  of  main  electric-railway  tracks  with 
underground  trolley  conduits,  from  $5  to  $20  per  lin. 
ft.  of  single  track.  A  fair  average  seems  to  be  about  $10. 

For  horse-railway  tracks,  about  $5  per  lin.ft. 


[41] 


The  excavation  price  does  not  include  the  relaying  of 
the  sidewalks  or  curb  or  repaying  the  streets,  within  the 
neat  lines  of  the  excavation ;  this  is  paid  for  at  prices  bid 
per  square  yard,  for  the  various  types  of  pavement.  All 
street  surfaces  are  first  repaved  with  Belgian  blocks  and 
maintained  by  the  contractor  for  six  months,  after  which 
the  final  form  of  new  pavement  is  laid. 

The  eight-hour  labor  law  is  strictly  applied  to  all  this 
work.  No  blasting  is  allowed  between  11  p.m.  and  7  a.m., 
and  of  course  all  charges  of  explosives  have  to  be  quite 
light  on  account  of  danger  to  the  timbering  or  adjacent 
buildings.  On  most  of  the  work  two  shifts  are  employed, 
the  men  generally  working  from  6  a.m.  to  2 :  30  p.m.  and 
from  3  p.m.  to  11 :  30  p.m.,  with  half  an  hour  for  a  meal. 

All,  or  nearly  all,  the  material  taken  from  the  excava- 
tion in  Manhattan  has  to  be  disposed  of,  usually  by  haul- 
age to  the  water  front,  where  it  is  loaded  on  scows  and 
towed  to  the  point  of  disposal.  This  involves  the  renting 


tion  is  nearly  all  in  earth.  A  small  amount  of  rock  is 
found  in  places,  but  not  enough  to  influence  the  meth- 
ods. On  account  of  the  timbering  and  the  necessary  sup- 
ports of  the  street  decking,  it  has  apparently  been  found 
most  convenient  and  practical  to  handle  all  the  material 
by  hand.  It  is  shoveled  into  buckets  of  about  1  yard 
capacity,  hauled  to  shafts,  hoisted  and  dumped  into 
storage  hoppers  holding  25  to  50  yards,  from  whence  it  is 
discharged  into  wagons.  Haulage  to  the  water  front  is 
done  almost  wholly  by  teams,  but  auto-trucks  are  used 
on  Section  1. 

A  very  efficient  and  convenient  arrangement  of  hoist 
and  storage  hoppers,  Pig.  46,  was  installed  at  Broadway 
and  Waverly  PL,  on  Section  4,  by  the  Dock  Contractor  Co. 
A  vacant  lot  permitted  the  construction  of  a  long  narrow 
head-house  parallel  to  the  street  and  over  the  sidewalk.  A 
telpher  was  arranged  over  the  shaft  and  hoppers,  which 
allowed  a  much  more  rapid,  because  better  controlled, 


FIG.  45.     TELPHER  HOIST  AT  74TH  ST.  AND  LEXINGTON  AVE. 


of  pier  or  dock  facilities  by  contractors  and  a  haul  vary- 
ing from  ^  to  1  or  2  miles  in  wagons  or  auto-trucks. 
The  latter,  holding  from  3  to  4  cu.yd.,  are  being  quite 
commonly  used,  and  are  generally  said  to  be  more  satis- 
factory and  cheaper  than  horse-drawn  wagons.  It  is 
necessary  that  they  be  fully  utilized — that  is,  that  there 
be  the  least  possible  delay  at  loading  and  unloading 
points ;  otherwise  the  overhead  charges,  chauffeur's  wages, 
and  interest  on  investment  amount  to  too  large  a  pro- 
portion of  the  unit  cost. 

Where  auto-trucks  are  used  for  disposal  of  excavation, 
a  storage  hopper  is  usually  provided  at  the  head  of  the 
shaft,  which  will  hold  at  least  one  load  (or  more,  depend- 
ing on  the  number  of  trucks  in  use,  and  the  kind  of 
material),  so  that  there  is  no  more  delay  in  loading  than 
that  necessary  to  open  the  mouth  of  the  hopper  and  fill 
the  truck.  The  general  practice  seems  to  be  to  use  hop- 
pers and  chutes  when  the  excavated  material  is  earth  or  a 
mixture  of  earth  and  boulders  and  to  use  some  form  of 
ekip  or  bucket  for  rock. 

On  the  Broadway  line   below   23rd   St.   the   excava- 


handling  of  the  buckets  than  is  possible  with  a  derrick 
boom.  A  structure  of  this  type  would  not  have  been 
permitted  in  front  of  an  occupied  building. 

On  one  section  on  Broadway,  where  the  excavation  was 
mostly  sand,  a  belt  conveyor  was  used  in  the  bottom 
which  dumped  the  material  into  a  hopper,  from  whence  it 
was  elevated  to  the  bin  above  the  street  by  an  endless 
chain  of  buckets. 

On  these  downtown  sections  fewer  shafts  are  permitted, 
and  they  are  usually  from  1200  to  1500  ft.  apart,  making 
the  necessary  maximum  haul  on  the  bottom  about  half 
that.  Track  of  24-in.  gage  is  generally  used,  two  or  some- 
times three  lines,  with  mules  for  haulage.  In  many 
places  on  the  upper  levels  between  timbers,  small  %-yd. 
cars  are  used,  which  are  pushed  by  hand  short  distances 
to  where  they  can  be  dumped  to  the  lower  level.  A  typi- 
cal bridge  over  the  street  for  handling  materials  is 
shown  in  Pig.  47. 

Where  the  line  crosses  Union  Square,  most  of  the  work 
was  done  in  open  cut,  an  electrically  operated  shovel  being 
used.  Shovels  and  trains  were  used  on  the  open-cut  work 


[42] 


of  the  Sea  Beach  line  in  Brooklyn,  and  part  of  the  Var- 
rick  St.  line  is  in  open  cut. 

The  rock  excavated  from  the  subways  is  of  little  general 
use  for  structural  purposes.  A  certain  amount  of  the 
best  of  it  is  permitted  to  be  used  in  any  walls  or 


FIG.  46.     HEADHOUSE  OVER  SHAFT  AT  WAVERLY  PL. 
AND  BROADWAY 

masses  of  concrete  over  30  in.  in  thickness,  and  some  of  it 
is  used  for  rubble  for  blocking  up  the  yokes  of  the  street- 
railway  tracks  in  Manhattan. 

BUCKETS  AND  SKIPS 

On  many  parts  of  the  work,  %-  to  1-yd.  buckets  as 
shown  at  A  and  B.  Fig.  48,  are  used.  These  are  handled 


plest  form  of  block  and  tackle  being  used  to  haul  out  and 
lift  the  boulders  or  pieces  of  rock  too  large  to  be  conven- 
iently handled  by  one  or  two  men. 

In  one  case  where  turntables  were  tried  opposite  the 
shaft,  the  tracks  being  arranged  as  shown  at  A,  Fig.  49, 
it  was  found  that  they  frequently  got  out  of  order  and 
caused  considerable  delay;  so  they  were  taken  out  and 
the  tracks  arranged  as  shown  at  B,  the  shaft  being  en- 
larged to  permit  of  this  being  done.  On  Sections  8  to  11 
on  Lexington  Ave.,  transfer  tables  were  used  at  the  shafts 
as  shown  in  Fig.  52. 

On  certain  sections  3-  to  4-yd.  skips  of  the  type  shown 
in  Fig.  48-C  are  used.  They  are  hoisted  to  the  surface, 
and  either  dumped  into  a  wagon  or  auto-truck  or  placed 
on  the  wagon  bed,  and  hauled  to  the  place  of  disposal, 
where  they  are  again  lifted  and  then  dumped.  The  skips 
are  handled  underground  on  small  cars  drawn  by  mules, 
or  in  one  case  where  the  timbering  was  very  close  and 
the  headroom  low,  pushed  by  hand,  the  work  being  ar- 
ranged so  that  there  was  a  down  grade  to  the  shaft. 

The  advantage  of  these  large  skips  over  the  smaller 
buckets  is  greater  facility  in  loading.  They  are  taken 
off  the  cars  and  placed  on  the  ground  at  the  working 
face,  a  hoisting  engine  with  a  fall  suspended  from  the 
timbering  of  the  street  decking  being  used  for  the 
purpose.  There  is  no  lift  for  the  shovelers,  and,  of 
course,  very  much  larger  pieces  of  rock  can  be  handled 
without  block-holing  and  handled  more  easily. 

On  Sections  8,  9,  10  and  11,  on  Lexington  Ave.,  a 
type  of  bucket  known  on  the  work  as  a  "battleship" 
(Fig.  43)  is  used.  These  buckets  hold  from  iy2  to 
2  yards;  they  are  handled  in  the  excavation  and  tun- 
nels of  these  sections  on  small  cars  (3-ft.  gage)  with 


FIG.  47.     BIIIDGE  AND  DERRICKS  AT  GRAND  ST.  AND  BROADWAY 


in  the  excavation  on  small  flat-cars  on  24-in..gage  track, 
hauled  by  mules  to  the  shafts,  hoisted  by  derricks  to  the 
surface  and  dumped  into  the  trucks  or  hoppers.  At  the 
face  of  the  cut  the  buckets  are  loaded  by  hand,  the  sim- 


cradles  shaped  to  fit.  The  cars  coast  down  grade  either 
to  or  from  the  working  face  as  the  case  may  be,  and  are 
hauled  up  grade  by  small  stationary  hoisting  engines. 
The  line  from  the  hoisting  engine  is  usually  carried  out 


143] 


by  hand,  and  this  method  of  haulage  does  not  seem  very 
efficient. 

The  buckets  are  hoisted  to  the  surface  by  derricks,  Pig. 
43,  or  telpher,  Pig.  45,  placed  on  wagon  beds  and  hauled 
to  the  dock  by  horses.  This  type  of  bucket  with  the  top 


.    A    .      ;.      .     ,  .. 
:  48.    DUMP  BUCKETS  FOR  HANDLING  MATERIAL  •. 

some  3!/2  or  4  ft.  above  the.ground  .(.as  it  remains  .on  the 
cars  while  being  loaded)  involves  a  fairly  high  lift  for  the 
shovelers,  and  the  necessity  of  -keeping  the  tracks  up  close 
to  the  face  does  not  permit  the  flexibility  which  is.  possible 
with  the  skips,  which  are  taken  off  the  cars  and  placed 
in  the  most  convenient  position  for  loading.  Many  of 
these  small  tunnel  cars  consist  merely  of  a  rectangular 
frame  of  6-in.  I-beams  to  which  the  axle  boxes  for  two 
axles  are  fastened.  Those  for  use  with  the  "battleships" 
have  two  or  three  wooden  cross-pieces  or  cradles  cut  to  fit. 
The  contracts  for  Sections  8,  10  and  11,  Lexington 
Ave.,  are  being  executed  by  the  Bradley  Contracting  Co., 
that  for  Section  9  by  Patrick  Alt-Govern  &  Co.  Nearly 
the  whole  length  of  the  lower  level  tracks  is  in  tunnel,  the 
excavation  of  which  is  described  separately,  but  the  upper- 
lejvel  •  double"  track  lias  generally  been  built  as  cut  "arid 
cover.  An  arrangement  has  been  made  whereby  the 
Bradley  Company  takes'  care  of  !  the  disposal' of  all  the 
material,  that '  from  the  upper  section  being  hauled  to 


from  12  to  15  ft.  high  and  mostly  earth  was  taken  off  the  ' 
whole  length  of  the   section,   this:  permitting   working 
access  to  the  whole  job,  for  underpinning,  support  of 
pipes,  conduits,  etc.     A  shaft  was  sunk  to  subgrade  at ' 
every  other  cross  street,  about  every  450  ft.,  and  outside 
the  main  excavation.    The  location  of  the  shafts  in  the  , 
cross  streets  is  shown  clearly  in  the  photographs,  Figs.  44  ' 
and  45.     From  this  shaft  a  cut  was  drifted  across  the 
full  width  of«the  work -and  the  excavation  carried  forward 
in  both  directions  from  it.     About  120  skips  were  used 
on  this  section,  and  about  400  yd.  of  rock  (place  meas- 
urement) was  handled  each  24  hours  from  the  two  work- 
ing faces  with  the  two  gantries. 

'  The  tower  form  of  timbering  (as  described  under  Tim- 
bering) was  used,  the  working  space  being  spanned  by 
eo'n'tihuous  I-beams  reaching  from  the  last  towers  to 
blocking  on  the  floor  of  the  first  lift,  as  shown  in  the 
sketch,  Fig.  50.  Two  side  cuts,  each  about  one-third  the 
widffrof  the  excavation,  were  driven  ahead  35  to  40  ft., 
then  the  center  was  blasted  sideways  into  these  cuts.  This, 


A  B 

KG.  49.     SKETCH  OF -TRACK  ARRANGEMENTS  AT  SHAFT 

tne  dock  at  96th  St.  and  the  East  Eiver,  and"  from  the 
lower  sections  to  76th  and  68th  Sts. 

'  The  use  of  these  skips  or  the  "battleships"  is  probably 
oi  greater  advantage  in  rock  excavation  than  in  eartlv 
as  some  kind  of  mechanical  apparatus  for  handling  the 
rock  is  generally  necessary  at  the  face  and  is  therefore 
available  to  handle  the  skips  on  and  off.  the  cars  and  to 
lo'ad  large  pieced  of  rock.  Small  power  shovels,  operated 
by  electricity  or  air,  are  often  used  for  loading  the  spoil 
on  underground  work,  but  on  most  of  the  subway  work, 
the  extensive  and  close  system  of  timbering  hardly  ad- 
mits of  their  use. 

The  system  used  for  the  rock  excavation  on  Section  13 
(McMullen,  Snare  &  Tri'est)  seems  to  be  quite  effective. 
Here  the  rock  face  is  25  to  35  ft.  high,  and  40  to  50  ft. 
wide.  After  the  street  decking  was  put  in,  a 'top  lift, 


(a) 


Long.    Sec+ions 


Plans 


FIG.  50.  -  SKETCH  ILLUSTRATING  PROGRESS  OF  EXCAVA- 
TION IN  DEEP  EOCK  TUNNEL  ON  SECTION  13, 
LEXINGTON  AVE. 

as  "will  be  seen,  protected  the  timbering,  at  least  to  a 
considerable  extent,  from  direct  blasting  against  it.  AVhen 
the  face 'at  the  center  was  advanced  40  ft.,  another  tower 
was  erected,  the  girders  were  moved  ahead,  the  process 
was  repeated,  etc. 

Two  double-drum  air  hoisting  engines  were  located 
back  from  the  face  on  top.  with  single  fall  lines  lead- 
ing over  sheaves  suspended-from  the  "timbers  of  the  street 
decking  above  the  working  space.  These'two  lines  (two 
on  each  side)  handled  the  larger  pieces  of  rock  and  the 
skips  on  and  off  the  cars,  and  were  also  used  in  handling 
timbers,  etc. 

DERRICKS  AND  GANTRIES 

On  Section  13,  Lexington  Ave.  (McMullen,  Snare  & 
Triest),  gantries,  as  shown  in  Fig.  44,  have  been  installed 
at  the  shafts,  instead  of  derricks,  for  hoisting  material  out 
of  the  excavation  and  for  lowering  the  structural  ma- 
terial. The  advantages  of  these  gantries  are  said  to  be 
greater  safety  to  the  public  in  the  streets,  greater  rigid- 
ity,'and  therefore  more  security;  better  speed  in  hoist- 
ing, easier  spotting  •  of  the  skips  over  the  wagon  bed. 
less  power  reqiiired  for  hoisting,  and  the  elimina- 


[44] 


tion  of  booming  up  and  down  with  loads.  It  is 
said  that  the  saving  of  power  (in  regard  to  which 
no  definite  data  are  available)  is  due  largely  to  the 
elimination  of  the  swinging  engines  which  are  neces- 
sary with  derricks.  It  is  also  stated  that  there  is  a 
considerable  saving  in  the  wire  hoisting  ropes,  which 
lasted  only  two  to  four  weeks  on  the  derricks,  but  which 
last  from  three  to  four  times  as  long  on  the  gantries. 

These  gantries  will  also  handle  heavy  loads  with  much 
greater  security;  those  now  in  use  have  handled  loads  up 
to  25  tons.  This  is  of  considerable  advantage  in  the  rock 
excavation,  as  it  permits  the  handling  of  large  rocks  with- 
out breaking  them  up.  They  are  so  arranged  that  from 
20  to  25  loaded  skips  can  be  stored  at  them  (see  Fig. 
44),  thus  permitting  night  work  when  the  teams  are 
not  available  to  haul  this  material  and  also  permit- 
ting considerable  flexibility.  This  latter  is  a  great  advan- 
tage, owing  to  the  difficulties  of  disposal,  which  is  de- 
pendent on  the  availability  of  the  scows,  a  somewhat  un- 
certain item  in  some  of  the  severe  winter  weather,  the  dif- 


where  more  latitude  was  allowed  in  the  matter  of  open- 
ing up  the  streets,  only  part  of  the  excavation  being 
decked  over,  the  excavated  material  was  handled  in  4-yd. 
Western  dump  cars  hauled  by  dinkeys  (3-ft.  gage)  to  the 
disposal  grounds  %  to  %  mile  distant. 

On  the  next  section  to  the  north  at  the  junction  of  the 
Southern  Boulevard  and  138th  St.,  a  model  49  Marion 
shovel  is  just  being  installed  for  loading  the  cars  and  a 
model  60  Marion  was  used  in  the  deep  rock  cut  through 
Franz  Sigel  Park,  on  the  northwest  end  of  Section  15. 

On  the  steep  hill  on  Lexington  Ave.  between  102nd  and 
103rd  St.  where  the  traffic  is  light  (on  account  of  the 
steepness  of  the  hill)  and  where  the  tunnel  with  all  four 
tracks  at  the  same  level  changes  to  a  cut-and-cover  sec- 
tion, one  side  of  the  street  was  left  open  and  a  cableway 
was  installed  for  handling  the  material. 

Varick  St.  is  being  widened  from  its  original  width 
of  about  60  ft.  to  100  ft.  and  the  excavation  in  this 
widened  portion  is  being  made  in  open  cut,  the  original 
width  of  the  street  being  decked  over  and  the  material 


FIG.  51.    A  EOCK  SLIDE,  LEXINGTON  AVE. 
SUBWAY 

ficulties  of  haulage  in  bad  weather,  and  many  other  fac- 
tors, as  already  noted.  The  teams  which  haul  the  spoil 
to  the  dock  work  only  eight  hours,  and  by  storing  the  ma- 
terial under  the  gantries,  delays  are  avoided  and  the  work 
is  accomplished  in  this  length  of  time.  On  this  work,  the 
big  stone  is  generally  loaded  into  the  skips  during  the 
day  and  the  finer  material,  which  must  be  shoveled,  is 
handled  by  the  night  shift. 

The  first  of  these  gantries  was  made  about  40  ft.  long 
and  22  ft.  high,  but  those  built  afterwards  were  made 
60  ft.  long  and  27  ft.  high,  thus  giving  more  storage 
room,  and  the  extra  height  greater  facility  in  handling 
some  of  the  structural  steel.  There  are  altogether  seven 
of  these  in  use  on  Section  13  and  one  shaft  with  a  der- 
rick. Their  use  on  Section  13  has  been  apparently  very 
successful,  but  it  is  to  be  noted  that  they  are  peculiarly 
well  adapted  to  the  conditions  there,  and  it  cannot  be 
assumed  that  they  would  replace  derricks  to  so  great  ad- 
vantage under  other  conditions. 

MISCELLANEOUS  EXCAVATION  METHODS 
On  the  first  section  north  of  the  Harlem  River  (Sec- 
tion 15,  Route  5 — Rodgers  and  Hagerty,  contractors), 


FIG.  52.     A  TRANSFER  PLATFORM,  LEXINGTON  AVE. 
SUBWAY 

under  it  taken  out  at  the  open  sides.  The  first  lift  of 
10  to  12  ft.  is  loaded  directly  into  wagons  by  shoveling, 
inclines  being  built  from  the  surface  down  to  this  depth. 
Much  of  the  excavation  is  sand,  and  below  the  first  lift 
this  is  loaded  into  1-yd.  V-shaped  Koppel  cars  which  are 
dumped  sideways  into  a  hopper,  under  which  runs  a  short 
belt  conveyor,  which  in  turn  carries  the  material  to  a 
bucket  elevator  which  raises  it  into  a  storage  hopper  above 
the  street  level. 

Steam  shovels  were  quite  generally  used  on  the  con- 
struction of  the  4th  Ave.,  Brooklyn,  lines  in  1909-10  and 
are  being  used  now  on  the  open-cut  work  of  the  Sea  Beach 
line,  but  generally  speaking,  very  little  use  is  made  of  me- 
chanical apparatus  of  any  kind  on  the  subway  excavation, 
most  of  the  excavated  material  being  shoveled  by  hand. 

DRILLING 

On  Section  13  the  drillers  work  in  two  8-hr,  shifts, 
from  6  a.m.  to  11  p.m.,  and  the  muckers  in  two  shifts, 
from  8  p.m.  to  1  a.m.  One  feature  of  considerable  inter- 
est is  the  quite  extensive  use  of  the  so-called  Jap  or 
hand  hammer  drill  with  hollow  drill  steel.  The  New  York 


[45] 


rock,  a  soft  to  medium  hard  gneiss  or  mica  schist,  seems 
to  lend  itself  particularly  well  to  the  operation  of  this 
kind  of  drill  in  excavations  where  most  of  the  holes  are 
down  holes.  The  type  which  is  in  most  general  use,  is 
the  Ingersoll-Rand  B.C.R.  33,  which  weighs  about  90  lb., 
using  air  at  80  to  90  lb.  pressure.  The  hollow  drill  steel 
is  usually  about  1%  in.  octagon,  the  holes  are  drilled 
dry,  the  air  through  the  steel  blowing  out  most  of  the 
dust,  therefore  keeping  the  holes  clean  and  consequently 
increasing  the  effectiveness  of  the  machines.  These  drills 
are  used  for  drilling  holes  to  depths  up  to  12  and  14 
ft.;  it  is  stated  that  they  require  from  50  to  75%  less  air 
at  the  same  pressure  than  the  usual  tripod  drill  does,  and 
only  one  man  is  required  to  operate  each  of  them.  The 
general  opinion  seems  to  be  that  unskilled  laborers  with 
very  little  instruction  could  use  these  drills,  though,  of 
course,  in  New  York  the  labor  unions  compel  the  em- 
ployment of  regular  union  drill  runners. 

On  Section  14  (McMullen  &  Hoff)  four  men  with  as 
many  drills  were  averaging  from  80  to  90  ft.  of  hole  per 
man  per  day  of  eight  hours.  There  was  one  record  of 
113  ft.  for  one  man  in  eight  hours.  It  was  considered  ad- 
visable to  keep  a  number  of  spare  drills  on  hand,  so  that 
in  case  anything  went  wrong,  there  was  no  delay,  and  any 
damaged  drill  could  be  taken  to  the  shops,  where  it  could 
be  carefully  repaired  by  a  competent  machinist,  even 
though  the  trouble  was  very  slight.  This  was  considered 
to  be  better  than  to  have  an  ordinary  drill  runner  try  to 
fix  it  with  the  spanner  or  sledge  hammer,  the  tools  usually 
used  by  them  when  anything  is  wrong  with  a  drill.  These 
drills  were  also  used  on  the  heavy  rock  excavation  of  Sec- 
tion 13,  a  cut  30  to  50  ft.  wide  and  as  many  feet  deep, 
with  excellent  results. 

On  some  sections  a  lighter  type  of  drill  weighing  about 
40  lb.  and  using  about  50  ft.  of  air  per  min.  is  being  used ; 
this  is  the  Ingersoll-Rand  B.R.C.  No.  430  or  so  called 
Jackhamer  type,  used  for  holes  up  to  6  and  8  ft.  in 
depth  using  %-in.  hollow  steel. 

Another  point  of  interest  is  the  almost  universal  use 
of  machine  drill  sharpeners,  nearly  all  of  which  are  of 
the  Leyner  type.  This  use  of  machine  sharpeners  is  pos- 
sibly due,  to  some  extent,  to  the  use  of  the  hollow  steel 
and  the  rose-shape  form  of  bit  generally  used  with  these 
hand  drills,  though  of  course,  it  has  been  shown  even 
with  the  old  type  of  cross  bit,  that  where  the  number  of 


drills  warranted,  the'  installation  of  a  drill  sharpener 
was  an  economy. 

It  was  noted  that  in  many  cases  the  heads  of  the  steel 
drills  had  sheared  square  off  just  back  of  the  head.  This 
type  of  failure  has  not  previously  come  to  the  writer's 
notice,  and  no  adequate  explanation  was  offered  by  the 
men  on  the  work,  but  it  would  seem  that  it  might  be 
due  to  the  severe  internal  stresses  set  up  by  the  much 
greater  force  used  in  the  machine  sharpeners  in  form- 
ing the  heads,  and  the  fact  that  possibly  in  these  ma- 
chine sharpeners,  the  steel  can  be,  and  is,  worked  at  a 
lower  temperature  than  by  hand. 

It  is  stated  by  the  contractors  on  Sec.  13  and  14  that 
the  general  breakage  and  wastage  of  steel  used  is  rather 
greater  than  with  the  ordinary  steel,  and,  of  course,  the 
hollow  steel  is  more  expensive,  but  it  is  thought  this  is 
much  more  than  compensated  by  the  greater  amount  of 
work  done.  The  Leyner  drill  sharpeners  are  used  to 
make  all  the  bolts  for  the  timbering  on  one  section, 
where  it  was  stated  that  400  bolts  were  headed  per 
hour. 

Electric  current  is  used  for  power  at  most  of  the  com- 
pressor plants,  and  air  is  usually  piped  to  all  points  of 
the  work  for  use  in  drills,  pneumatic  riveters,  etc.  In 
some  cases  the  air  is  used  for  operating  hoists  and  der- 
ricks, in  other  cases  electric  power  is  used  directly  for 
this  purpose;  this  apparently  is  governed  most  generally 
by  the  plant  the  contractor  may  have  had  on  hand,  but 
the  use  of  air  for  hoists  and  derricks,  so  long  as  it  has 
to  be  installed  in  any  event,  seems  to  be  the  most  satis- 
factory and  most  generally  used. 

Various  schemes  for  heating  the  air  during  cold 
weather  were  noted,  some  of  the  apparatus  home-made 
and  other  manufactured  especially  for  the  purpose.  On 
one  section  (McMullen,  Snare  &  Triest)  an  upright  coil 
of  about  6  to  8  rings,  15  to  18  inches  in  diameter,  was 
made  in  the  air  line  near  the  point  where  it  was  to  be 
used,  and  a  fire  built  and  maintained  inside  the  coil. 
In  another  case  a  piece  of  6-  or  8-in.  pipe  about  3  ft.  long 
was  capped  at  the  ends  to  take  the  regular  air  line  (about 
2  in.)  and  a  fire  built  under  the  larger  section.  These 
home-made  schemes  are  probably  somewhat  wasteful 
of  fuel,  but  this  amounts  to  very  little  and  they  probably 
stand  up  better  under  the  rough  usage  they  get  on  this 
kind  of  work  than  the  manufactured  heaters. 


T461 


Underpinning  Building's  Along 

the  Line 


Under  the  general  heading  of  "Protection  of  Adjacent 
Buildings,"  the  specifications  provide  for  three  classes  of 
work. 

A.  Buildings  "which  are  supported  on  firm  soils"  and 
bearing  such  a  relative  position  in  regard  to  the  subway 
structure  that  a  slope  "represented  by  1  ft.  vertical  to 
%  ft.  horizontal,  incline  downward  from  the  bottom  outer 
edge  of  the  building  foundation,  passes  beneath  the  bot- 
tom outer  edge  of  the  completed  subway  structure"  have 
to  be  taken  care  of  by  the  contractor,  and  such  cost  as 
there  may  be  is  included  in  the  price  for  excavation. 

B.  When  necessary  to  secure  adjacent  buildings  or  to 
prevent  bringing  an   unusual  pressure  on   the   subway 


STRICT 


•W  W: 

so/Tk- —  40 Hpftv 

C 


i 

•g  Beam\( 


ixcqration 
Line 


'' (Support  ty 
Cantilever) 


Rubble  Wall 

....  This  part  of  the 
..-  wall  was  rebut  If 
to  bear  directly 
on  the  beams 


•Caisson  shaft 

filled  with  concrete 


FIG. 


53.    SKETCHES   ILLUSTRATING  VARIOUS   TYPICAL 
METHODS  OF  UNDERPINNING  BUILDINGS 

A  —  Underpinning  by  needles,  ordinary  form. 

B  —  Underpinning  by  pile  and  short  cross  I-beams. 

C  —  Underpinning  by  piers  and  I-beam  between. 

D  —  Underpinning  by  cantilever. 

E  —  Underpinning  by  caisson  and  I-beams. 

structure  when  completed,  the  contractors  are  required  to 
"safely  and  permanently  underpin  adjacent  buildings  the 
foundations  of  which  are  above  the  bottom  of  the  adjacent 
subway  excavation."  This  work  is  paid  for  at  a  price 
bid  per  front  foot  of  the  building.  The  latter  are 
classified  according  to  height,  less  than  seven  stories,  sev- 
en to  twelve  stories,  and  over  twelve  stories.  The  prices 
for  this  work  on  contracts  let  so  far  range  from  $50  to 
$100  per  front  foot  for  7-story  buildings  and  from  $75  to 
$200  with  an  average  of  about  $150  for  buildings  7  to 
12  stories.  The  prices  are,  however,  very  irregular  and 
there  is  little  distinction  in  the  bidding  between  uptown 
and  downtown.  Bids  for  underpinning  buildings  over 
12  stories  range  from  $90  to  $400  per  front  foot  and  are 
too  few  and  erratic  to  be  of  any  use  as  a  guide  to  the  cost 
of  the  work. 

C.  In  certain  cases  where  underpinning  is  not  con- 
sidered necessary  but  where  buildings  have  to  be  secured 
and  maintained  during  construction,  there  is  a  price  bid 
per  front  foot  for  "maintaining,  protecting  and  secur- 
ing." These  prices  range  from  $15  to  $60  and  average 
about  $40. 


It  is  generally  required  that  underpinning  be  carried 
down  to  solid  rock  or  to  at  least  2  ft.  below  the  lowest 
excavation  for  the  subway,  if  rock  is  not  encountered  be- 
fore that  depth  is  reached. 

Often  when  the  necessary  excavation  for  the  subway 
structure  takes  a  fairly  large  proportion  of  the  width  of 
the  street,  the  excavation  of  the  "first  lift"  is  carried  out 
to  the  full  width  of  the  street  between  building  lines  and 
to  the  depth  of  the  cellar,  thus  providing  easy  access  for 
working  as  is  shown  in  Fig.  53A.  The  excavation  of  this 
first  10  ft.  is  generally  first  carried  ahead  the  whole  length 
of  the  section,  or  for  a  considerable  portion  of  it,  and  this 
is  followed  by  the  underpinning  before  any  further  ex- 
cavation is  undertaken. 

Probably  the  most  common  way  of  supporting  ordi- 
nary buildings  is  to  temporarily  carry  the  walls  to  be  sup- 
ported on  needles,  generally  I-beams,  as  shown  in  Fig. 
53A  and  extend  the  foundation  walls  down  to  rock  if  this 
is  not  too  deep. 

In  cases  where  the  depth  of  rock  or  to  the  required  bot- 
tom of  foundation  is  deep,  piers  (from  2  to  3  ft.  square 
for  ordinary  buildings  5  or  6  stories  high)  are  usually 
sunk  at  intervals  of  10  to  15  ft.  The  spacing  of 
the  piers  depends,  of  course,  on  the  position  of  the  piers 
or  columns  of  the  building  which  require  direct  support, 
and  the  front  wall  of  the  building  between  the  piers  is 
supported  on  two  or  more  I-beams  spanning  the  space 
between  these  piers.  The  excavation  of  the  pits  for  the 
piers  is  usually  made  by  hand,  the  well  being  sheeted,  and 
the  piers  are  built  of  concrete.  In  some  cases,  instead 
of  the  concrete  piers,  12-in.  pipes  in  short  lengths  are 
sunk  either  by  driving  with  a  weight  or  with  a  water  jet, 
the  subsequent  procedure  being  the  same. 

To  avoid  supporting  the  buildings  on  needles,  two 
methods  have  been  used,  somewhat  similar  in  principle. 
Concrete  piers  2  ft.  square  are  sunk  to  rock  in  pairs, 
one  inside  and  one  outside  the  wall,  each  pair  10  to 
12  ft.  apart,  or  instead  of  the  piers,  12-in.  wrought- 
iron  pipes  in  lengths  of  about  4  ft.  with  inside 
sleeve  couplings  are  sunk  and  filled  with  concrete, 
the  tops  of  these  piers  or  pipes  being  20  to  30  in.  be- 
low the  cellar  floor.  I-beams  of  suitable  size  (50  to 
60  Ib.  generally  for  ordinary  buildings)  are  then  laid 
on  top  of  these  piers  or  pipes  parallel  and  adjacent  to  the 
walls  of  the  buildings;  small  holes  are  then  broken 
through  the  wall  and  smaller  I-beams  put  through  span- 
ning the  first  two  and  the  walls  caught  up  on  these,  as 
shown  in  the  sketch  in  Fig.  53B. 

On  one  section  where  a  building  of  moderate  size  had 
to  be  taken  care  of,  piers  were  sunk  to  rock  (or  to  the 
required  depth)  and  then  the  wells  were  widened  out  at 
the  top  in  the  direction  of  the  line  of  the  building,  as 
shown  in  Fig.  53C,  and  filled  with  concrete,  in  which  re- 
inforcing rods  were  placed.  These  piers  were  30  to  40 
ft.  apart  and  the  space  between  them  was  spanned  by  two 
30-in.,  200-lb.  Bethlehem  beams,  which  were  placed  in 
niches  cut  in  the  wall  to  receive  them. 

On  Section  14,  Lexington  Ave.,  W.  Melvin,  Superin- 
tendent for  the  McMullen  &  Hoff  Co.,  devised  a  form  of 
shield  on  the  principle  of  the  tunnel  shield,  but  reduced 


[47] 


to  its  simplest  elements,  to  sink  3-ft.  6-in.  cylinders  ver- 
tically for  underpinning.  The  apparatus  is  shown  by 
the  drawings,  Fig.  55,  and,  as  will  be  seen,  consists  sim- 
ply of  a  cylinder  of  ^-in.  boiler  iron  about  3  ft.  long 
with  a  3x4-in.  angle  bent  to  circular  form  to  fit  inside 
just  back  from  the  lower  end.  Pour  segments,  as  shown 
in  the  drawing,  form  an  18-in.  ring,  which  is  added  to  the 


/Doorway^ 


Reinforcing 
Rods     " 


Plan 


2,  %"°rods,  twisted,  p/aced 
in  each  casing 
D-Depth  of pif  be/ow  sidena/k 
All  plates /f  steel,  ifrlZ'xlf 
one  ro  each  casing 
All  C.I.  splices  for  each  casing 
a/ikejsee  detail) 
Casing  filled  with  concrete 


Pia.  54. 


iJL 


Detail  of  C.I. Splice 

for  10'Diam.  Pipe 

Casing 


UNDERPINNING  BUILDINGS  WITH  STEEL-PIPE 
PILES  FILLED  WITH  CONCRETE 


bottom  of  the  caisson  inside  the  tail  of  the  shield  as  this 
latter  is  shoved  down.  The  shield  is  "shoved"  by  four 
jack  bolts,  bearing  against  the  3x4-in.  angle  of  the  shield 
and  reacting  against  the  last  ring. 

The  material  is  removed  by  means  of  small  buckets 
which  are  raised  by  a  hand  winch  and  taken  out  of  the 
top  through  the  air  lock.  On  account  of  the  small  work- 
ing compartment  only  one  man  can  work  at  the  excava- 
tion, but  usually  there  is  another  puddling  the  joints  and 
sealing  the  shaft. 

The  shield,  of  course,  was  left  in  the  bottom  when  the 
caisson  was  concreted.  These  caissons  were  sunk  about 
20  to  25  ft.  apart,  directly  under  the  front  walls  of  the 
buildings,  the  location  depending  on  the  location  of  the 
main  columns  or  piers  which  it  was  desirable  to  support 
directly.  The  space  between  them  was  spanned  by  two  26- 
in.,  150-lb.  Bethlehem  beams  on  which  the  wall  was 
supported  directly,  as  shown  in  Fig.  53E. 
,  At  one  point  on  Section  13,  Lexington  Ave.,  where  the 
rock  was  quite  near  the  surface  and  the  necessary  excava- 
tion close  to  the  building  line,  a  slip  occurred  in  the  rock, 
endangering  the  front  of  the  building.  In  order  to  avoid 
blocking  up  in  the  excavation,  long  I-beams  were  used  as 
cantilevers,  blocked  up  in  the  cellar  just  back  of  the  front 
wall  and  running  back  under  the  back  wall,  against  which 
they  were  blocked  and  which  afforded  the  necessary  re- 
action, as  shown  in  the  sketch  in  Fig.  53D. 

On  Sections  8,  9,  10  and  11,  Lexington  Ave.,  three 
methods  were  used :  First,  the  common  one  of  support- 
ing the  buildings  on  needles  while  the  walls  were  carried 
down  in  trenches  to  rock,  this  being  usually  adopted  when 
the  rock  was  not  deep.  Second,  piers  of  concrete  about 
5  to  6  ft.  wide  and  8  to  10  ft.  long  were  sunk  to  rock  or 
subgrade  and  spanned  by  two  or  sometimes  three  I-beams 


on  which  the  building  wall  was  carried.  This  method 
was  usually  used  where  the  rock  or  subgrade  was  deep, 
say  10  ft.  or  more  below  the  basement  floor  of  the  build- 
ing. Third,  1 0-in.  iron  pipes  in  lengths  of  3  to  5  ft.  with 
inside  sleeve  couplings  were  sunk  under  the  walls  and 
capped  with  I-beams,  as  shown  in  Fig.  54.  The  pipes 
were  forced  down  by  jackscrews  reacting  against  the 
walls  of  the  building,  and  were  put  down  under  columns 
or  sections  of  the  wall  which  carried  the  load.  They 
were  sunk  dry  and  the  material  inside  excavated  with 
small  orange-peel  scoops.  The  small  boulders  encoun- 
tered were  taken  out  by  a  sort  of  net  on  the  end  of  a  pole 
called  a  "snare."  They  were  supposed  to  be  sunk  to  rock, 
sealed  to  it  by  a  rich  cement  mortar,  and  filled  with  con- 
crete in  which  were  embedded  two  %-in.  square  steel 
rods. 

This  method  of  underpinning  is  quite  effective  and 
safe  in  many  cases  and,  of  course,  is  very  much  cheaper 
than  either  of  the  first  two  methods,  if  the  foundations 
have  to  be  carried  down  to  any  great  depth.  The  de- 
fects are  that  it  is  sometimes  difficult  to  tell  if  the  pipes 


(,...•/£' "holes  for 
/"jack    bolts 
\ \-3-6" 


Section    A-A 


1     fl            ~ 

-A 

J 



a                                      j 

-R 

i 
! 

Y 

I'Jack 
Bolts 
{ 

L.3W 

¥/>/ 


4   I  Jack  Bo/ts 
-•'i'Bolts 


£  Plate 


Segments  for  Air 
Cylinders 


Section  B-B  EH.  N... 

Shield'  -for  Sinking  Caissons 

FIG.  55.    SECTIONAL  CAISSONS  OF  CAST  IRON  SUNK  WITH 

SHIELD 

are  on  solid  rock  or  on  a  boulder,  and  if  the  excavation 
for  the  subway  or  other  purpose  comes  close  to  the  build- 
ing line,  the  front  of  the  pipes  may  be  uncovered,  leaving 
them  as  practically  unsupported  columns.  So  far  as 
could  be  learned,  however,  where  they  have  been  used 
so  far,  they  have  served  their  purpose  and  no  actual 
difficulty  or  failure  has  been  encountered.  This  work 
was  done  by  the  Underpinning  &  Foundation  Co.,  under 
a  subcontract  from  the  principal  contractors. 


[48], 


A  method  which  obviates  the  necessit}'  of  supporting 
the  buildings  on  needles  was  developed  and  used  on  Sec- 
tions 1  and  3  of  the  Broadway  line.  It  consists  essen- 
tially in  tying  the  foundation  columns  together  with  a 


FIG.  56.    PUTTING  DOWN  HOLLOW  STEEL  PILE  WITH 
HYDRAULIC  JACK  REACTING  AGAINST  BUILDING 

reinforced-concrete  mattress  or  girder,  as  shown  in  Fig. 
59,  then  sinking  pits  or  piles  under  it  to  the  required 
depth.  Built-up  steel  girders  or  I-beams  are  first  laid 


along  on  either  side  of  the  columns  and  parallel  to  the 
face  of  the  building,  at  about  the  level  of  the  basement 
floor,  or  just  below  it,-  one  outside  and  one  inside  and 
tied  to  each  column  and  to  each  other.  These  girders 
are  made  up  of  short  sections,  on  account  of  the  con- 
fined space  in  which  they  have  to  be  handled,  and  a 
.convenient"  form  is  one  made  up  of  four  angles  latticed 
together,  and  riveted  so  as  to  be  continuous  for  the  length 
of  the  front  of  the  building  (see  Fig.  58),  though  I- 
Ijeams  are  used  in  some  cases.  Light  hitches  are  cut  in 
the  piers  to  get  a  firm  bearing,  and  the  girders  or  I- 
beams  are  tied  together  firmly  with  rods  or  sometimes 
with  steel-wire  ropes,  the  whole  being  then  concreted, 
making  a  continuous  reinforced-concrete  girder  support- 
ing-the  whole -front.  The  photograph,  Fig.  58,  shows 
in  the  foreground  the  two  latticed  girders  and  behind 
that  the  completely  concreted  beam  or  girder. 

Rectangular  pits  are  then  sunk  at  intervals  under  this 
girder,  as  shown  in  the  sketch,  Fig.  59,  and  in  spaces  be- 
tween the  column  footings  so  that  the  ground  under  these 
latter  remains  undisturbed.  The  pits  are  sheeted  with 
horizontal  sheeting,  and  are  sunk  to  the  necessary  depth, 
i.e.,  to  2  or  3  ft.  below  the  subgrade  of  the  subway  struc- 
ture, and  filled  with  concrete.  Care  is  taken  not  to  have 
the  open  pits  close  together.  About  two  at  a  time,  some 
distance  apart,  are  put  down,  filled  and  blocked  under  the 
concrete  girder  before  others  are  started.  If  water  is  en- 
t-ountered,  hollow  steel  piles  in  short  sections  are  sunk 
from  the  bottom  of  the  pits  below  the  water  level  and 
filled  with  concrete.  All  piles  are  tested  by  hydraulic 
pressure  to  take  up  any  slight  settlement. 

There  are  two  methods  of  sinking  these  hollow  steel 
piles  which  are  quite  extensively  used,  one  by  the  use  of 
hydraulic-  or  screw-jacks  reacting  against  the  building 
above,  as  shown  in  the  photograph,  Fig.  56,  and  the  sec- 
ond, to  drive  them  by  a  hammer.  The  first  is,  it  is 
stated,  a  patented  process.  Where  the  hammer  is  used 
it  generally  consists  solely  of  a  weight,  about  300  lb., 


FIG.  57.     UNDERPINNING  WITH  XEEDLES  BUILDING  AT 

459  BROADWAY 

[49] 


FIG.  58.     UNDERPINNING  WITH  A  LATTICED 

GlBDER 


suspanded  from  a  rope  passing  over  a  single  block  at- 
tached to  the  floor  above  the  pit,  and  running  to  a  small 
single-drum  hoist.  The  fall  is  usually  only  a  few  feet 
and  the  hammer  is  guided  by  hand  by  a  man  standing 
near  the  pile  being  driven.  A  square  cast-iron  cap  is 
used  on  top  of  the  pile. 

An  interesting  detail  of  the  horizontal  sheeting  so  gen- 
erally used  in  sinking  the  pits  for  underpinning  and  other 
purposes  is  the  method  of  chamfering  the  corners  of  the 
boards  so  as  to  allow  of  packing  the  ground  solid  behind 
them  as  they  are  placed  (see  Fig.  60).  The  boards  on 
two  opposite  sides  are  cut  so  that  they  fit  inside  those  on 
the  other  sides,  making  a  brace,  and  short  blocks  are 

r~t  r~i      r~i  r~i       r~i    r~i      n 


LJ 


Building 
Column 
•---; 

Reinforced  Concrete  Oircfer 


,12 Piles 


FIG.  59.     SKETCH  ILLUSTRATING  UNDERPINNING  WITH 
REINFORCED-CONCRETE  GIBDER 

spiked  on  to  hold  the  short  sides  as  shown  in  the  plan. 
The  long  sides  are  placed  first,  and  made  to  give  a  firm 
driving  fit  to  the  short  ones.  Each  width  is  firmly  packed 
as  it  is  placed. 

The  pits  are  filled  with  concrete  up  to  within  about  12 
or  15  in.  of  the  bottom  of  the  concrete  girder.  When  the 
concrete  in  the  pit  has  set,  short  sections  of  I-beams  are 
placed  on  top  of  it  and  wedges  are  firmly  driven  between 
these  I-beams  and  the  bottom  of  the  foundation  girder. 
This  holds  the  latter  while  the  other  pits  are  being  put 
down,  the  shrinkage  in  the  concrete  in  the  pits  being 
taken  up  from  time  to  time  by  the  wedges  and  the  whole 
finally  completely  filled  in,  after  all  shrinkage  and  settle- 
ment of  the  new  foundation  have  taken  place. 

The  foundations  of  the  Havemeyer  Building  (14  stor- 
ies) are  on  spread  brick  piers  on  wooden  piles,  the  bottom 
of  the  brick  and  the  top  of  the  piles  being  at  approxi- 
mately the  level  of  the  floor  of  the  subway.  To  protect 
these  foundations,  additional  hollow  steel  piles  were  sunk 
under  the  front  edges  of  the  building  piers  and  then  a 
double  row  of  steel  sheet  piling  10  or  12  ft.  long  and  with 
a  space  of  about  3  ft.  between  the  rows  was  driven  as 
additional  protection.  This  acts  as  a  coffer-dam  and  not 
only  will  tend  to  prevent  any  disturbance  of  the  ground 


Sec.A-B 

FIG.  60.  HORIZONTAL  SHEETING  FOR  SINKING  PITS 

around  the  piles,  but  also  to  retain  the  level  of  the  ground 
water. 

In  turning  from   Church  St.  through  Vesey   St.   to 
Broadway,   it   was   necessary   to   obtain    easements   un- 


der private  property  at  each  of  the  corners  in  order 
to  get  around.  One  of  these  is  under  Trinity  Par- 
ish House  and  the  other  under  the  old  Astor  House. 
That  portion  of  the  latter  under  which  the  tunnel 
passes  was  dismantled  and  taken  down,  the  city  agree- 
ing to  provide  foundations  for  a  new  building  along  each 
street  line.  Open  trenches  were  sunk  through  the  sand 


Section  B-B 


Section  A-A 


61. 


LOCATION  OF  SUBWAY  TUNNELS  UNDER 
TRINITY  PARISH  HOUSE 


to  a  depth  of  about  30  ft.  and  from  the  bottom  of  these 
trenches  pneumatic  caissons  are  being  sunk  to  the  re- 
quired depth.  The  sinking  of  the  caissons  is  done  under 
a  special  subcontract  by  the  Foundation  Company. 

The  Trinity  Parish  House  is  a  four-story  brownstone 
building  about  30  ft.  wide  and  160  ft.  long.  The  tunnels 
pass  under  it  as  shown  in  the  sketch,  Fig.  61.  Rectangu- 
lar pits  were  sunk  as  shown  by  the  drawing,  there  being 
115  of  these  pits.  Part  of  these  pits  supported  the 
building  directly  ;  at  other  places  the  walls  are  supported 
on  cross-girders  over  the  tunnel,  as  indicated  on  the 
sketch.  With  the  exception  of  part  of  the  ground  floor 
and  basement  the  building  has  been  continuously  in  use 
during  the  whole  operation. 

A  method  of  underpinning  was  developed  on  Sec.  3  of 
Route  5  (see  Fig.  42)  by  the  Underpinning  &  Foundation 


[H.~^A  A 

FIG.  62.    UNDERPINNING  WITH  NEEDLES  6-STORY  BUILD- 
ING, BROADWAY  AND  17TH  ST. 

Co.,  which  consists  essentially  of  the  construction  of  a  re- 
taining-wall,  the  face  of  which  is  practically  at  the  neat 
line  of  the  structure.  This  is  made  practicable  by  reason 
of  the  fact  that  along  most  of  the  route  the  space  under- 
neath the  sidewalks  is  occupied  by  vaults  used  by  the 
owners  of  the  adjacent  buildings  under  revocable  per- 
mits from  the  city.  The  width  of  the  subway  structure 
makes  it  necessary  to  occupy  part  of  these  vaults,  though 
any  remaining  portion  is  afterward  restored  for  the  use 
of  the  abutting  property  owners.  Most  of  the  excavation 
of  this  section  is  in  sand  and  the  depth  is  comparatively 
shallow.  The  contractor,  therefore,  took  advantage  of 
the  situation  to  build  his  sidewalls  as  retaining  walk, 


[50] 


working  from  the  bottom  of  the  vaults  before  commenc- 
ing the  main  excavation.  This  effectually  prevented  any 
disturbance  of  the  ground  under  the  building  and  less- 


mostly  below  ground-water  level  and  quite  deep,  the 
method  above  described  did  not  wholly  apply.  It  served, 
however,  for  the  upper  level  and  steel  sheeting  was  then 
driven  between  the  outer  tracks  and  the  inner  pair,  to 
enable  these  latter  to  be  taken  down  to  the  required  depth. 


FIG.  63.    TEMPOEABY  SUPPORT  FOB  ELEVATED-RAILWAY 
COLUMNS 

ened  the  amount  of  timber,  as  no  bracing  for  the  sides 
was  required.  The  retaining  wall  was  built  in  sections 
by  sinking  4  ft.  square  pits  or  wells  (using  the  horizon- 
tal sheeting)  separately,  and  some  distance  apart,  then 


HOLLOW  PILES  FOB  FOOTING  OF  ELEVATED- 
RAILWAY  COLUMNS 


The  six-story  brick  building  at  the  corner  of  Broadway 
and  17th  St.  was  held  on  needles  while  it  was  under- 
pinned, and  is  a  good  example  of  what  this  method  in- 
volves for  a  heavy  building.  The  length  of  the  front  which 
was  supported  is  about  25  ft.,  and  eighteen  2J-in.  I- 
beams  each  about  25  ft.  long  were  required  to  hold  the 
weight.  There  were  two  piers  between  the  corners  and  the 
three  spaces  between  them  were  filled  with  heavy  timber 
bracing  and  blocking  before  operations  were  commenced, 


Elevated    R. 

\R.  Girder 

Streei 
Level 


FIG.  64.    SUPPORT  OF  ELEVATED-RAILWAY  COLUMNS 
ox  CHURCH  ST. 

intermediate  pits  were  put  down  and  finally  the  whole 
closed  up  to  make  a  continuous  wall. 

At  the  lower  end  of  this  section,  the  two  middle  tracks 
are  depressed  for  the  Canal  St.  connection,  and  as  this  is 


FIG.  66.  TIMBER  A-FBAME  WITH  EYE-BAB  CLAMP  SUP- 
POBTING  ELEVATED-RAILWAY  COLUMNS,  CHUBCH  ST. 

as  is  shown  in  the  sketch,  Fig.  62.  The  I-beams  were  used 
in  groups  of  three,  supported  on  a  continuous  grillage 
built  up  on  the  cellar  floor  inside  and  on  the  vault  floor 
outside.  Hitches  were  cut,  one  at  a  time  in  the  sides  of 
the  columns  to  take  the  three  I-beams,  and  the  whole  load 
finally  transferred  to  them  while  the  foundations  were 
carried  down. 


[51] 


ELKVATED-RAILWAY  COLUMXS 

The  columns  of  the  elevated  railway  as  originally  built 
were  generally  supported  beneath  the  surface  of  the  street 
on  spread  brick  footings,  the  removal  of  which  is,  made 
necessary  by  the  construction  of  the  subway.  Tempor- 
ary supports  as  shown  in  the  photograph,  Fig.  63,  are 
built  to  hold  the  elevated  structure  during  construction 
and  considerable  care  is  necessary  to  prevent  any  settle- 
ment and  to  provide  as  nearly  as  possible  absolute  safety; 
On  Sec.  1,  Eoute  5,  which  is  under  Church  St.  and  the 
Sixth  Ave.  Elevated,  the  A-frame  supporting  the  cross- 
girder  above  the  column  is  supported  on  timber  bents 
resting  on  steel  piles.  The  spread  brick  footings  are  urn 
covered  and  spaces  are  cleared  at  the  two  sides  of  the 
structure  in  each  of  which  three  14-in.  steel  piles  are  sunk 
to  below  subgrade  and  to  a  firm  bearing ;  these  are  capped 
on  each  side  by  a  reinforced-concrete  beam  on  which  a 
perpendicular  timber  bent  is  erected  to  about  the  level 
of  the  street  surface  as  shown  in  the  sketch,  Fig.  64. 
These  bents  are  about  16  ft.  apart  and  an  A-frame 
is  then  erected  on  them.  The  legs  of  the  A-frame 
are  held  together  by  eye-bars  and  pins  or  timber  brac- 


ing, as  shown  in  Fig.,  66.  When  the  final  support 
of  the  columns  is. to  be  below  or. at  subgrade,  clusters  of 
hollow  steel  piles  .are.  driven  and  capped  with  rein- 
forced concrete,  to  form  the  new  footing,  as  shown 
in  the  photograph,  Fig.  65.  In  many  cases,  however^ 
the  new  column  footings  are  carried  directly  on  thq 
roof  of  the  completed  subway  structure. 

The  method  of  support  adopted  where  the  construction, 
of  a  new  sewer,  on  Third  Ave.,  required  temporary  supt 
port  of  one  pair  of  columns,  is  shown  in  the  photograph^ 
Fig.  66,  the  structure,  being  blocked  up  from  two  pairs  o£ 
girders  laid  direct  on  blocks  on  the  paved  surface  of  the, 
street. 

On  West  Broadway,  at  the  -  lower  end .  of  the  SeventlJ 
Ave.-Varick  St.  line,  the  elevated  columns  are  supported 
above  the  street  surface- by  a  timber  tower.  Immediately 
below  this  and  supporting  it  are  two  heavy  30-in.  Bethlet 
hem  beams  about  2.0  ft.-- long,  laid  on  either  side  of  the) 
brick  footing  parallel  to  the  street  line.  Both  ends  of  thes^ 
are  in  turn  supported -by  a  pair  of  24-in.  I-beams  which, 
rest  on  timber  blocks  on  the  ground  outside  of  the  bricl| 
footings. 


• 


• 


[0-4 


•Is  im  City  Streets 


THe  Lexington  Ave.  Tunnels 


With  the  exception  of  the  tunnels  under  the  rivers, 
referred  to  in  the  next  article,  practically  the  only  parts 
of  the  subway  lines  as  now  laid  out,  to  be  built  as  true 
tunnels,  are  those  under  Lexington  Ave.  for  the  two 
lower-level  tracks  from  about  53rd  St.  to  78th  St.,  and 
for  all  four  tracks  from  about  91st  St.  to  102nd 
St.  The  total  length  of  these  four  sections  is  about  2.6 
miles,  of  which  about  2  miles  is  to  be  built  in  tunnel. 
The  tunnels  on  Sec.  9  are  being  driven  in  part  by  Messrs. 
Douglas  &  Shailer,  under  a  subcontract  for  P.  McGovern 
&  Co.  The  rest  are  parts  of  Sec.  8,  10  and  11,  and  are 
being  built  by  the  Bradley  Contracting  Co. 

Xo  particularly  new  methods  of  driving  these  tun- 
nels or  of  handling  the  material  have  been  used,  but  some 
features  of  the  work  are  of  interest  on  account  of  the  dif- 
ficult and  uncertain  nature  of  the  rock  which  has  been 
encountered.  This  is  the  typical  gneiss  or  mica  schist 
which  underlies  the  whole  of  Manhattan,  varying  from 
quite  hard  to  very  soft  and  partially  disintegrated  mate- 
rial, containing  many  seams  and  dipping  and  striking  very 
irregularly,  thus  tending  to  cause  slips  and  slides,  which 
the  utmost  vigilance  and  care  cannot  always  avoid.  Driv- 
ing a  tunnel,  therefore,  or  even  making  an  open  cut 
through  this  kind  of  material  under  a  street  carrying 
heavy  city  traffic,  and  with  important  buildings  on  both 
sides  of  it  close  to  the  work,  requires  most  careful  meth- 
ods of  excavation. 

On  Sec.  11,  the  situation  is  complicated  by  the  change 
from  double-deck  two-track  tunnels,  one  over  the  other, 
to  a  four-track  section  with  all  the  tracks  at  one  level, 
making  a  tunnel  section  of  practically  rectangular  shape 
16  ft.  high  and  nearly  60  ft.  wide  (see  Fig.  68-1). 

A  power  plant  which  supplies  air  to  all  four  of  these 
sections  was  established  by  the  Bradley  Contracting  Co., 
at  96th  St.  and  the  East  Eiver.  It  contains  five  compres- 
sors, each  of  a  rated  capacity  of  about  2100  cu.ft.  of  free 
air  per  min.,  which  is  piped  through  a  10-in.  main  to 
all  sections,  the  distance  from  the  power  house  to  the 
center  of  the  farthest  section  being  about  2y2  miles. 
Comparatively  little  trouble  has  been  experienced  with 
this  line,  though,  of  course,  with  four  separate  and  fairly 
large  organizations  depending  on  one  source  for  their 
supply  of  air,  there  have  been  times  occasionally  when  all 
would  be  working  or  attempting  to  work  at  full  ca- 
pacity and  the  pressure  would  consequently  drop. 

A  supplementary  compressor  of  about  1500-cu.ft.  ca- 
pacity, connected  to  an  electric  motor  for  use  in  emer- 
gencies, has  been  installed  in  a  part  of  the  completed  sub- 
way on  Sec.  9.  at  T"th-81st  St.,  but  so  far  it  has  not  ac- 
tually been  used.  There  has  been  some  trouble  on  the 
long  main-feed  lines  with  freezing  in  cold  weather,  but 
nothing  of  importance.  The  main  is  carried  underneath 
the  decking  of  the  street. 

The  Bradley  Contracting  Co.  arranged  for  the  hauling 
and  disposal  of  the  muck  from  Sec.  9.  as  well  as  from 
all  its  own  sections,  so  the  same  type  of  buckets  are  used 
throughout  all  four  sections ;  the}'  are  the  so  called  bat- 
tleships already  referred  to  (in  the  article  on  excavation). 

In  the  tunnels,  four  small  power  shovels  (Marion 
model  40)  were  used  for  handling  the  muck  in  as  many 


headings,  where  there  was  room  for  them,  but  a  great 
deal  of  the  material  was  handled  by  hand  shoveling. 
Some  experiments  were  made  with  other  types  of  mer 
chanical  excavators,  designed  for  use  in  a  more  limited 
space  than  that  necessary  for  the  operation  of  a  shovel, 
but  they  were  not  successful  enough  to  warrant  their 
continued  use. 

The  buckets,  placed  on  small  four-wheel  cars  (Fig.  66, 
lower  view),  were  hauled  back  and  forth  between  the 
shafts  and  the  headings  by  various  means,  but  no  me- 
chanical locomotive  power  was  used.  Single-drum  air 
hoisting  machines  were  arranged  on  platforms  above  the 
floor  of  the  tunnel  to  haul  the  cars  up  grade,  either  the 
loads  out  of  the  heading  or  the  empties  back  as  the  case 
might  be,  the  cars  being  allowed  to  coast  down  grade.  A 
single  haulage  line  was  used,  the  end  being  carried  back 
by  hand  or  by  a  mule. 

Where  the  rock  was  good  the  full  section  of  double 
track  was  usually  taken  out  by  driving  a  top  center  head- 
ing about  8  ft.  high  and  12  ft.  wide,  keeping  the  enlarge- 
ment close  up.  The  heading  was  pulled  by  the  usual  Y- 
shaped  center  cut,  with  necessary  side  rounds,  20  to  40 
holes  6  to  8  ft.  deep,  according  to  the  character  of  the 
rock,  being  required  for  the  whole  heading.  About  3  Ib. 
of  60%  forcite  was  required  per  cu.yd.  in  the  headings 
in  hard  rock;  40%  was  used  in  the  softer  rock. 

In  one  case  a  pilot  heading  was  first  driven  all  the  way 
through  between  two  of  the  shafts  to  permit  better  venti- 
lation, especially  for  the  erection  of  the  structure,  which 
it  was  desired  to  keep  fairly  close  up  to  the  excavation. 

Timbering  was  required  to  support  the  rock  in  many 
places,  and  although  segmental  timbering  was  used,  the 
arch  was  so  flat  that  some  center  supports  were  almost  al- 
ways required.  The  original  design  for  the  double-track 
tunnels  provided  for  a  reinforced-concrete  center  wall, 
but  here  as  in  the  use  of  this  class  of  material  in  the  cut- 
and-cover  sections,  where  the  ground  or  the  street  surface 
required  continuous  support,  it  was  found  to  be  difficult 
to  make  a  good  job  with  it.  The  type  of  structure  shown 
in  Fig.  9  permits  the  construction  of  the  center  wall  with 
the  two  haunches,  as  shown  in  outline,  before  the  rest 
of  the  structure  is  built  and  permits  support  on  the  per- 
manent steel  structure  at  once.  The  method  is  shown 
also  in  the  sketch,  Fig.  67,  which  shows  the  various  steps 
of  construction  in  the  double  deck,  double-track  tunnels 
on  Sec.  11  and  also  incidentally  the  enlargement  for  the 
upper  level  local  station  at  96th  St. 

Figs.  69  and  70  show  typical  methods  of  supporting 
the  timbering  and  the  rock  above,  where  the  latter  was 
generally  fairly  good.  The  methods  used  varied  in  de- 
tail in  different  headings,  but  in  general  were  more  or  less 
alike.  The  flatness  of  the  arch  will  be  noted  and  the 
supports  on  either  side  of  the  center  wall,  permitting  the 
construction  of  this  latter  and  the  transference  to  it  of 
the  load,  thus  permitting  the  construction  of  the  two 
arches. 

Near  the  upper  end  of  Sec.  8  and  9,  from  56th  to  78th 
St.,  very  soft  disintegrated  rock,  carrying  considerable 
water,  was  found,  necessitating  typical  soft-ground  tun- 
neling methods.  Timbered  side  drifts  were  driven  for 


[53] 


The  general  appearance  of  this  timber  section  is  shown 
in  the  upper  left  view  above,  but  in  some  parts  of 
the  work  where  the  ground  was  particularly  heavy,  the 
space  between  the  timber  rings  was  filled  with  concrete, 
as  soon  as  possible  after  they  were  erected,  and  the  ground 
overhead  was  thoroughly  grouted.  Even  then  it  was  neces- 
sary to  use  some  temporary  supports  for  the  center.  De- 
tails of  two  types  of  timbering  used  are  shown  in  Figs. 
69  and  70. 

As  is  indicated  in  this  latter  drawing,  the  wall  plates 
were  sometimes  supported  on  a  ledge  of  rock,  but  more 
often  were  posted  down  to  subgrade  when  the  bench  was 
excavated.  The  raking  braces  shown  were  usually  only 
used  temporarily  to  help  support  the  wall  plate  while  the 
posts  were  set  under  in  very  soft  material,  but  occasion- 
ally they  were  left  in. 

Fig.  71  shows  a  method  of  timbering  used  as  part  of 
Sec.  9  south  of  78th  St.,  where  the  rock,  while  quite  hard, 
required  support  to  prevent  slides  or  the  possible  move- 


Two  VIEWS  IK  LEXINGTON  AVE.  TUNNEL 

Segmental  roof  timbering  (upper).     Shovel  and  car   (battleship)  lor  handling  muck  (lower). 


the  wall  plates,  segmental  timbering  tightly  lagged  was 
erected  from  them  with  about  twelve  inches  between  each 
ring,  crown  bars  and  poling  boards  were  used,  but  the 
latter  were  not  usually  driven,  as  the  rock  would  hold  for 
a  short  time.  The  method  actually  used  was  really  to 
place  lagging  over  the  top  of  the  arch  in  the  position 
of  poling  boards,  wedged  down  at  one  end,  over  the  last 
ring  erected,  in  the  position  in  which  poling  boards  would 
usually  be  driven.  These  projected  forward  over  the 
position  of  the  next  ring  and  were  blocked  up  from  it 
after  it  was  erected.  This  slight  variation  from  the 
method  of  placing  the  lagging  provided  some  protection 
from  small  dropping  rocks,  and  was  more  easily  accom- 
plished than  driving  the  poling  boards,  which  would 
have  been  difficult  in  the  material  excavated. 


ment  of  large  masses.  A  center  top  heading  was  driven 
and  as  soon  as  the  enlargement  was  made,  which  was  kept 
close  up,  the  timber  was  erected,  as  shown  in  the  "first 
stage"  cross-section.  In  the  "second  stage"  the  two  pairs 
of  continuous  I-beams  are  placed  to  span  the  bench  ex- 
cavation as  shown  in  the  longitudinal  section  in  Fig.  70. 
These  I-beams  were  joined  with  long  splices  to  develop 
full  strength  at  the  joints  and  were  made  continuous 
throughout  the  work.  The  muck  from  the  heading  and 
enlargement  was  brought  out  in  small  buckets  on  the 
tracks,  laid  on  the  cross-braces  at  the  springing  line  and 
dumped  into  the  buckets  on  the  tracks  below,  at  a  point 
back  of  the  face  of  the  bench. 

All   timber  is   provided   and  placed   by   the   contrac- 
tor at  his  own  expense,  the  cost  being  included  in  the 


[54] 


-• 


rrmfejecH**) 

A  B    (I)       C  D 

TRANSITION  FROM  DOUBLE  DECK  TO  FOUR  TRACKS 


DIAGRAMS  SHOWING  METHOD  OF  ROOF  SUPPORT  FROM  CENTER 

PARTITION  WALL -SECT.  II  R.5  LEXINGTON  AVE. ,._,,, A 

FIG.  67 


indicfffo  dn  vt,f*>n 
cf/xrxpuss  yfs**eter»cvn 
«fHO?OfCATCMN6UPPORIAL  UP  PORTAL  AT  103'!'  ST. 

(H)  FIG.  68 


urrunn  rterrrruiuA 
METHOD  OF  CATCHING 


Cross-  Section 


FIG. 69  -  TIMBERING     METHODS. SECTION  8 
LEXINGTON  AVE.  TUNNEL 


Section   A-B 

•5>-74-™ST.) 

(Y) 


Longitudinal    Section 


FIG.70-TIMBERING    METHOD.  SECTION  9  -  LEXINGTON  AVE.  TUNNEL  (X&XY) 

LEXINGTON      AVE.      TUNNEL 


FIG. 71-  SKETCHES  SHOWING 
TIMBERING  SUPPORTS  ETC.  SECT.  9 

_    Jill  Frame 

Blocfrrig- 


ffeyu/ar  tt'Segmenfs 


Tbr+  SeoHon 
of  Stage 
It 


FtartSec. 

of 
Sta^e  I 


FIG.7Z    CROSS-  SECTION  AND  PART 
ELEVATION  OF  VESEY  STREETT 
CAST-IRON  LINED  TUNNEL 


Heading 
\  Excavation 


Section  -rhi-ough  Web 
Detail    of  Jill     Frame 


Detail     of     Plates 


—  .-    —  —  ,-i— 

Jadmg&rr     4'*$.Tie       ff/'       6x1  Frorrt 
races      a+C         trfS      Sfrfffrfers     Bearing  Braces 


Invert, 
Lxcavation 


Cross -Sections  of  Trame 
FIG.  74--  SKETCHES  SHOWING  MEErtS    METHOD   OF  TUNNELING     (a.b.c.d) 
VESCY      ST.    TUNNEL 


[55] 


excavation  price.  The  extra  excavation  necessary  to  place 
the  timbers  outside  the  lines  of  the  structure  is  also  at 
the  contractor's  expense,  the  payment  line  being  confined 
to  the  neat  line  of  the  structure.  Concrete  placed  between 
the  timbers,  however,  is  paid  for  where  ordered,  as  is  also 
the  grouting. 

At  some  places  a  center  top  heading  was  driven  ahead, 
then  the  enlargement  was  made  all  on  one  side  just  large 
enough  to  permit  the  steel  and  concrete  structure  for  one 
track  to  be  built  in  it,  then  the  further  enlargement  was 
made  for  the  second  tunnel,  the  top  of  the  center  wall 
forming  the  abutment  for  the  arch  first  erected  being 
necessarily  braced  to  the  sides  until  the  second  arch  was 
erected.  This  method  obviated  the  necessity  of  anything 
but  occasional  support  of  the  rock  where  there  appeared 
to  be  a  tendency  to  slip. 

On  Sec.  8  and  9,  the  cut-and-cover  excavation  for  the 
upper-level  tracks  was  quite  generally  completed  and  the 
structure  erected  in  it  before  the  tunnel  underneath  was 
driven.  No  damage  to  the  upper  structure  or  difficulty 
of  moment  has  been  experienced  clue  to  this  method  of 
procedure  except  in  one  or  two  cases,  where  the  extremely 
heavy  rains  of  last  fall,  working  under  the  completed 
upper  structure,  washed  some  of  the  material  under  it, 
into  the  excavation  of  the  tunnel  below,  the  heading  of 
which  happened  at  that  time  to  be  in  very  soft  disin- 
tegrated rock.  The  upper  tunnel  structure  at  this  point 
was  temporarily  supported  by  heavy  timbers  and  girders 
which  spanned  the  washed-out  portion  and  the  latter  was 
then  thoroughly  grouted  and  the  trouble  remedied.  Close 
watoh  was  kept  at  all  times  of  the  upper  tunnel  at  points 
just  above  the  places  where  work  was  being  carried  on 
below,  and  any  indications  of  trouble,  as  were  shown  in 
one  or  two  cases  by  small  cracks,  were  investigated  and 
the  ground  below  thoroughly  grouted  if  this  appeared 
necessary.  The  efficiency  of  this  grouting  under  high 
pressure  was  shown  in  one  case  where  grouting  was  done 
from  below,  the  grout  being  forced  up  into  the  upper 
tunnel. 

Just  north  of  98th  St.,  the  two  upper  tunnels  spread 
out,  and  as  soon  as  they  get  far  enough  apart,  drop  down 
to  the  level  of  the  lower  tunnels,  until  all  four  are  at 
the  same  grade,  as  shown  in  Fig.  68-1.  Working  from 
the  shaft  at  97th  St.  toward  the  north,  the  two  lower  tun- 
nels are  being  driven  first  and  the  steel  and  concrete  struc- 
ture erected  in  them,  then  the  two  upper  tunnels  are  to 
be  driven  at  the  sides.  The  cross-section  C  will  show 
the  necessity  of  this,  as  it  will  easily  be  seen  that  the  cor- 
ners X  and  Y  will  probably  break  through,  and  the  char- 
acter of  the  rock  is  such  that  it  would  hardly  be  possible 
to  hold  up  the  mass  between. 

At  the  upper  end  of  this  section  at  102nd  St.,  working 
southerly  in  the  four-track  section  (Fig.  68),  the  method 
which  has  been  developed  and  started  is  based  on  the  idea 
of  driving  one  side  of  the  tunnel  first  for  a  distance  of 
about  80  ft.,  then  erecting  the  structure  in  it,  then  start- 
ing the  second  tunnel,  and  so  on,  thereby  avoiding  having 
the  excavation  open  for  more  than  the  width  of  one  tun- 
nel at  once. 

Some  difficulty  was  experienced  in  catching  up  some 
of  the  portals,  a  typical  method  of  overcoming  it  being 
shown  in  the  sketch,  Fig.  68-11.  At  the  beginning  of  the 
double-deck  tunnel  just  south  of  95th  St.,  the  lower  level 
vras  driven  through,  the  steel  structure  erected  and  con- 


creted, then  the  upper  level  was  worked  back  from  the 
inside  to  the  portal,  as  shown. 

At  the  portal  at  102nd  St.,  where  the  four  tracks 
are  all  at  one  level,  a  side  drift  was  driven  for  a 
length  of  almost  80  ft.,  a  crosscut  was  then  made  from 
this  drift  the  full  width  of  the  structure,  as  shown  in  the 
sketch,  Fig.  68-111,  and  the  structure  then  erected  so 
that  the  rock  was  caught  up  and  then  the  excavation  car- 
ried back  out  to  the  portal. 

VESEY  ST.  IRON-LINED  TUNNELS 

On  Sec.  1-A  of  the  Broadway  line  there  is  a  reversed 
curve  where  the  route  passes  from  Church  St.  through 
Vesey  St.  to  Broadway,  and  the  narrowness  of  the  streets 
makes  it  necessary  to  pass  under  private  property  at  each 
of  the  corners.  The  material  for  a  considerable  depth 
(50  to  60  ft.)  below  the  streets  in  this  section  is  sand, 
but  it  is  comparatively  dry  down  to  the  level  of  the  bot- 
tom of  the  subway  structure,  which  latter  is  about  -±  ft. 
below  M.H.W. 

Easements  were  obtained  under  the  two  pieces  of  pri- 
vate property  referred  to,  namely,  the  Trinity  Parish 
House  and  the  old  Astor  Hotel,  on  condition  that  the 
former  should  be  properly  supported  on  new  foundations, 
bridged  over  the  tunnel,  and  that  on  the  site  of  the  lat- 
ter (which  was  razed)  suitable  foundations  for  the  heav- 
iest type  of  building  should  be  provided,  also,  of  course, 
bridged  over  the  tunnel  where  this  passed  through  them. 
Under  these  conditions  it  was  thought  desirable  to  de- 
sign two  separate  circular  cast-iron  lined  tunnels  or 
tubes.  The  two  tubes  together  have  a  length  of  about 
1200  ft.  and  will  require  about  4350  tons  of  cast  iron  for 
the  lining  and  about  17,000  cu.yd.  of  concrete. 

As  these  sections  of  iron-lined  tunnel  are  comparatively 
short,  the  use  of  the  usual  type  of  pneumatic  shield  for 
driving  them  would  have  involved  a  somewhat  high  cost 
for  plant,  chargeable  to  only  a  small  amount  of  work. 
Besides  this,  the  driving  of  tunnels  by  the  shield  method 
on  curves  of  as  small  radius  as  this  is  a  somewhat  diffi- 
cult operation,  though  on  the  Hudson  &  Manhattan  E.E. 
there  is  at  the  corner  of  Morton  and  Greenwich  St.  a 
curve  of  150-ft.  radius,  which  was  successfully  driven  by 
the  use  of  the  shield.  The  diameter  of  these  tunnels  was, 
however,  some  3y2  ft.  less  than  those  at  Vesey  St. 

The  contractors,  Messrs.  F.  L.  Crawford,  Inc.,  adopted 
therefore,  for  this  work,  a  method  developed  by  them  and 
their  engineer,  J.  C.  Meem,  M.  Am.  Soc.  C.  E.,  some 
years  ago  in  the  construction  of  some  large  circular  brick 
trunk  sewers  in  Brooklyn  and  which  was  quite  fully  de- 
scribed in  a  paper  presented  by  Mr.  Meem  to  the  Brook- 
lyn Engineers'  Club  in  May,  1905. 

This  method  as  modified  for  the  construction  of  these 
tunnels  is  shown  quite  clearly  in  the  drawings  and  photo- 
graphs, Figs.  73  and  74.  A  top  heading  is  driven,  the 
roof  protection  being  afforded  by  the  five  sectional  shields 
or  jills,  a  detail  of  which  is  shown  in  Fig.  74d,  and  the 
front  end  in  the  photograph,  Fig.  73-1.  These  are  shoved 
ahead  by  hydraulic  jacks,  and  a  lining  of  2-in.  hardwood 
lagging  put  in  behind  them,  under  the  tail;  this  is  tem- 
porarily supported  by  crown  bars  and  blocking,  which 
in  turn  are  supported  by  segmental  timbers  consisting 
of  the  cap  made  of  a  16xl2-in.  cut  on  top  to  chords  of  the 
curve  and  flat  underneath  to  take  the  posts,  and  the  two 
side  pieces,  as  shown  in  the  drawing,  Fig.  74,  a  and  b,  and 
the  photograph,  Fig.  73-3. 


[56] 


From  the  heading,  the  sides  are  worked  down  to  about 
the  springing  line  (horizontal  diameter)  by  placing  the 
5-ft.  lengths  of  horizontal  lagging  much  as  it  is  placed 
in  the  pits  for  underpinning  and  as  shown  in  the  photo- 
graph, Fig.  73-3.  To  get  out  the  excavation  in  the  center 


The  girder  itself  is  made  up  in  12-ft.  sections  arranged 
BO  that  the  rear  section  can  be  detached  and  bolted  on  to 
the  front,  overlapping  about  3  ft.  Extra  holes  are  pro- 
vided so  that  the  progress  can  be  made  either  in  a  straight 
line  or  deflected  to  fit  the  curvature.  The  girder  flanges 


FIG.   73.     VIEWS  IK   YESEY   ST.  TUXXEL 

1.     Temporary  bracing  and  lagging.  2.     Iron-lined    tunnel    and    pilot    girder. 

3.     Segmental   roof   shields — jllls.  4.     Tunnel  and  pilot  girder,  erector. 


below  the  heading,  the  top  cap  is  carried  temporarily  on 
the  20-in.  I-beams  shown  in  Fig.  74 (a),  spanning  the 
working  space  from  the  erected  intermediate  sill  (the  one 
just  above  the  center  of  the  circle)  to  the  firm  ground 
in  the  bottom  of  the  heading. 

This  permits  the  advancement  of  the  so  called  pilot 
girder,  which  is  advanced  along  the  center  in  the  position 
of  the  pilot  tunnel  of  the  old  Anderson  &  Barr  method. 
The  girder  in  the  present  instance,  however,  only  serves 
a  purpose  similar  to  that  of  the  temporary  I-beams  above, 
that  of  supporting  the  overhead  structure  of  timber  block- 
ing, over  the  working  space,  its  rear  end  being  siipported 
on  blocking  from  the  erected  iron  lining,  its  front  end 
on  the  unexcavated  ground  of  the  second  lift  just  below 
the  center.  The  photographs.  Fig.  73  (2  and  4^.  show  the 
method  of  using  the  erector  around  the  pilot  girder,  and 
the  latter  part  of  the  tunnel  under  the  Trinity  Parish 
House,  which  had  previously  been  underpinned  and  the 
space  above  the  tunnel  bridged  over. 


are  8x8x^-in.  angles,  and  the  latticing  4x4xi4-in.  angles. 
The  girders  are  3  ft.  on  centers  held  together  and  braced 
by  4x%-in.  bars.  The  roof  load  of  the  tunnel,  which  the 
girder  supports,  is  estimated  to  be  about  10  tons  per  lin. 
ft.,  but  the  girders  are  designed  to  carry  a  maximum 
load  of  40  tons  per  lin.ft.  for  spans  of  12  ft.,  thus  pro- 
viding for  uncertainty  and  probable  irregularity  of  load- 
ing and  support. 

The  hardwood  lagging  is  left  in  place  when  the  cast- 
iron  lining  is  erected.  This  latter  weighs  approximately 
6600  Ib.  per  lin.ft.  of  tunnel  and  it  is  cast  in  the  usual 
segmental  form.  The  individual  segments  are  6  ft.  2  in. 
long.  20  in.  wide  and  weigh  about  1500  Ib.  each.  Every 
fifth  ring  is  a  taper  ring  for  the  curves,  other  taper  rings 
(with  considerably  less  taper)  are  provided  for  correct- 
ing the  alignment  when  this  becomes  necessary. 

In  making  the  excavation  the  ground  at  the  breasts,  as 
well  as  the  sides,  is  usually  held  at  all  points  by  lagging 
or  poling  bounds  to  prevent  any  subsidence. 


[57] 


Tlhie 


Tike  Harlem  Riweir 


The  general  design  of  these  tunnels  is  shown  in  the 
cross-section,  Fig.  76.  It  was  determined  by  two  prin- 
cipal factors :  First,  the  necessity  on  account  of  the  con- 
ditions under  which  the  approaches  were  located  of  keep- 
ing the  tunnels  as  near  the  surface  as  possible ;  second,  the 
desirability  of  obtaining  a  minimum  total  width  to  avoid 
encroachments  on  valuable  private  property. 

The  methods  developed  in  the  construction  of  the  tun- 
nels under  the  Harlem  River  for  the  original  subway  (see 
ENGINEERING  NEWS,  Oct.  13,  1904)  and  at  DetroitJ  for 
the  tunnels  of  the  Michigan  Central  Ry.,  had  shown  the 
practicability  of  sinking  tubes  from  the  surface,  and  these 
methods  also  permitted  much  closer  spacing  than  would 
have  been  possible  with  shield-driven  tunnels,  which  lat- 
ter would  necessarily  or  at  least  most  conveniently  have 
had  to  be  circular,  with  a  reasonable  space,  say  10  ft.  or 
so  between  each  tube.  It  may  be  noted,  however,  that  the 
tunnels  which  had  been  previously  built  by  sinking  from 
the  surface  were  for  two  tracks  only,  whereas,  the  new 
Harlem  River  tunnel  is  for  four. 

Bids  were  originally  called  for  late  in  1910  on  two 
types,  H  and  K.  Type  H  was  similar  to  that  of  the 
original  Harlem  River  tubes,  and  type  K  similar  to  the 
Detroit  River  tubes. 

The  bid  prices  were  as  follows,  per  lin.ft.  of  four-track 
tube: 

Type  K — Lowest  $1925,  highest  $3000,  per  lin.ft.  of  four-track 

tube. 
Type  H — Lowest  $2200,  highest  $3000,  per  lin.ft.  of  four-track 

tube. 

Before  the  contracts  were  awarded  it  was  decided  to 
change  the  dimensions;  the  bids  were  therefore  rejected 
and  the  work  readvertised,  this  time  calling  for  bids  on 
three  types,  H,  K  and  L.  Types  H  and  K  remained  the 
same  except  for  the  changes  in  dimensions.  Type  L  was 
a  modification  of  Type  H,  having  the  four  tubes  all  to- 
gether instead  of  in  two  pairs. 

The  bids  on  the  latter  two  types  were  all  rejected  and 
that  of  Messrs.  Arthur  McMullen  and  Olaf  Hoff,  the  low- 
est bidders  on  type  K,  was  accepted ;  the  range  of  bids  at 
this  last  letting  for  the  tube-tunnel  section  having  been 
as  follows,  per  lin.ft.  of  four-track  tube : 

Type  K,  $1500  to  $1800,  8  bids. 
Type  H,  $1650  to  $2000,  3  bids. 
Type  L,  $1550  to  $2000,  6  bids. 

The  contract  price  of  $1500,  equal  to  $375  per  lin.ft.  of 
track,  may  be  compared  with  the  cost  of  the  Detroit  River 
Tunnels,  which  has  been  given  as  $332.29,  exclusive  of 
contractors'  profits.  However,  the  inside  diameter  of  the 
Detroit  tunnels  was  20  ft.,  as  compared  with  16  ft.  6  in. 
for  the  Harlem  River  tubes. 

The  method  adopted  by  the  contractors  with  very  few 
modifications  was  that  developed  for  the  construction  of 
the  Detroit  River  Tunnels,  which  has  been  quite  fully 
described!  in  various  papers  and  articles  in  the  technical 
press.  The  article  in  ENGINEERING  NEWS,  of  Feb.  15, 
1906,  is  interesting  as  showing  the  development  of  the 
process.  It  consists  essentially  in  the  erection  of  the 
steel  tubes  in  suitable  lengths  on  shore,  bulkheading  the 
ends  to  get  flotation,  launching  these  sections,  towing 


JEng.  News,  Feb.  15,  1906,  and  Mar.  17,  1910.  Proc.  Inst. 
C.  E.,  Vol.  CLXXXV,  1910-1911.  Trans.  Am.  Soc.  C.  E.,  Vol. 
LXXIV,  1911. 


them  to  the  site  which  has  previously  been  dredged  to  the 
required  depth,  and  sinking  them  in  place  by  filling  them 
with  water  (see  photographs  in  Fig.  75).  The  concrete 
is  then  deposited  around  the  outside  by  means  of  tremies, 
the  sections  unwatered  and  the  inner  concrete  lining 
placed.  This  method,  of  course,  obviates  the  necessity  of 
general  work  in  compressed  air,  though  divers  are  used 
to  a  limited  extent. 

The  accompanying  drawings  and  photographs  show  the 
essential  details  of  the  structure  and  the  methods  of  sink- 
ing and  as  the  general  methods  have  already  been  so  fully 
described,  it  seems  only  necessary  to  call  attention  to  such 
changes  and  improvements  as  experience  and  the  par- 
ticular conditions  of  the  Harlem  River  work  have  shown 
to  be  desirable.  The  tunnel  was  divided  into  five  sections, 
four  of  220  ft.  each  and  one  of  200  ft. 

In  the  Detroit  River  tubes,  the  circular  stiffening 
angles,  which  are  spaced  about  8  ft.  apart,  were  placed  on 
the  inside,  as  then  it  was  thought  necessary  to  provide 
temporary  interior  bracing  in  the  form  of  the  spokes  of  a 
wheel.  Experience  showed,  however,  that  this  might  be 
dispensed  with,  and  on  the  Harlem  River  tubes  the  stif- 
fening angles  were  placed  on  the  outside.  This  permitted 
the  construction  of  the  braces  or  struts  to  the  wooden  bulk- 
heads or  forms  at  the  sides,  which  materially  decreased 
the  necessary  thickness  of  the  timber,  which  latter,  in 
the  case  of  the  Detroit  tunnels,  was  6  in.  thick  at  the 
bottom  and  4  in.  thick  at  the  top.  For  the  Harlem  River 
Tunnels,  4-in.  plank  was  used  for  the  lower  half  and  3- 
in.  for  the  upper. 

The  manner  of  making  a  tight  joint  be.tween  each  of 
the  sections  shows  an  important  modification  in  the  di- 
rection of  simplicity.  The  old  joint  with  the  pilot  pin  is 
shown  in  the  drawing,  Fig.  77a.  This  joint  was  not  al- 
together satisfactory,  as  it  was  somewhat  difficult  to  fit 
and  the  rubber  gaskets  are,  of  course,  perishable.  The 
new  joint  (see  Fig.  77b)  is  a  butt  joint  instead  of  an 
overlapping  or  sleeve  joint,  and  the  bolts  on  the  outside 
are  easily  placed  by  divers.  The  inner  plate,  which,  of 
course,  is  riveted  in  place  after  the  tubes  are  unwa- 
tered, assures  practical  water-tightness.  It  will  be  re- 
membered that  the  concrete  is  placed  outside  this  joint 
before  the  tubes  are  unwatered,  and  tests  made  with  the 
concrete  deposited  by  the  tremies  at  Detroit  showed  it  to 
be  of  very  good  quality,  sufficiently  impervious  to  prevent 
any  leakage  of  moment.  The  space  between  the  joint 
in  the  shell  and  the  inner  plate  is  to  be  filled  with  grout 
after  the  latter  is  riveted  in  place.  There  is  a  pilot  pin 
on  each  of  the  two  outer  tubes,  and  when  both  are  home, 
the  accuracy  of  the  construction  insures  a  good  fit  every- 
where. The  unwatering  of  the  tunnels  has  shown  these 
joints  to  be  remarkably  tight. 

Attention  may  be  called  to  the  method  of  tying  the 
tubes  and  the  partition  walls  together,  as  shown  in  detail, 
Fig.  76.  Reinforcement  of  1-in.  square  rods  is  placed 
in  the  inner  concrete  lining.  Longitudinal  rods  are  spaced 
12  in.  apart  at  the  sides.  It  is  probable  that  this  might  be 
omitted  and  still  leave  the  tunnels  entirely  safe,  but  is  an 
added  precaution  thought  advisable  in  view  of  the  com- 
parative novelty  of  the  method. 


[53] 


FIG.  75.     VIEWS  in  THE  HARLEM  RIVEI:  TUBES  PUKING  COXSTRUCTIOX 

A      Construction,    partial.      B — Construction,    completed.       C — TowinK  to  site.     D  and  E — Sinking.     F — Inside. 


Before  launching  a  section,  the  two  outer  tubes  were 
tightly  bulkheaded  at  both  ends,  but  the  inner  tube?  only 
about  4  ft.  up,  as  shown  in  the  sketch.  Fig.  78,  that  is,  just 
high  enough  to  provide  flotation  while  beinsr  towed  to 
the  site.  The  outer  ends  of  the  end  sections  are.  of  course, 
tightly  bulkheaded  on  all  four  tubes  with  bulkheads  to 
-tand  total  pressure  for  the  depth,  so  they  will  hold  when 
the  tube?  are  unwatered.  Photograph  T5D  shows  the  south- 


erly end  of  the  first  section  A  with  all  the  bulkheads  in. 
At  Detroit  the  tubes  were  actually  launched,  by  allowing 
them  to  slide  down  the  ways  as  a  ship  is  launched;  on 
the  Harlem  River,  however,  it  was  thought  best  to  build 
the  structure  on  an  open  platform  over  the  water,  so  that 
flat-decked  lighters  could  be  floated  underneath  to  lift 
them  off.  The  lighters  used  were  water  boats  which  could 
\w  filled  by  the  opening  of  valves  provided  for  the  purpose 


[59] 


f&0.-. 

rrrz — • — j;  •-• — •— — -T.^..... -.. •-.  ••.-. -.^ . — .•_  ..  •,-r. .,.  _,.., 


FI6.76-SECTIONS    or   HARLEM     RIVER    TUNNEL 


Upper Ami- 

frStSS.  \ 


_jLi 


<* 

Pile  •.. 
fJriver 

$ 

^ 

w 

/ 


Fie.77-DETAILS    OF      PILOT    PIN    AND     JOINT 


fHARLEM  RIVER) 


(llbiej 


River  surface 
/          when  fubes 
are  filled 
with  wafer 


WHCMLM/KHU  ______  ...............  _________  A*  l'-4'     lf//£HSffH-et/i>r>/fiUlSAfffffOffOAm7://" 

s'-ii"    WHCN  STRUCTURE  is  FULL  oFwtm  A  -3o'-2" 


Upper  Semi-' 

"XMS, 


FI6.79-FLOATIN6  EQUIPMENT  FOR  SINKING  TUBES 


FI6.78-DETAIL      OF      BULKHEADS 

HARI^EM      RIVER-     TUNNEL 


4-9-'—     >1*-/5">T<- 3-3" 


. —         * 

C..L  of  Jacks'' 

Section 
x-x 


olta 

o;       10! 


oooo 
. 


\<.-£-V!<- 


3'- 


FIG.  81 

DETAILS  OF   DOUBLE    ROOF   SHIELD 
TO  BE  USED  FOR  TUNNEL  UNDER  N.Y.C.etH.R.R. 
JUST  NORTH  OF  THE  HARLEM   RIVER 


FI6.8O-TUNNELS    UNDER     N.  Y.  C.  8c  H.  R.  R. 

(SMOWINS  DETAILS 
OF  TIMBERED  DRIFTS 


n+  Elevation  of  Left  Shield 


N.T.C.  &  H.R.R.  TUNNEL 


[60] 


and  emptied  by  pumps.  They  were  floated  \inder  at  low 
water,  raised  by  the  tide  to  lift  the  tubes  off  the  plat- 
form, and  then  when  the  tubes  were  moved  over  deep  wa- 
ter were  scuttled,  leaving  the  tubes  floating.  On  account 
of  the  narrowness  of  the  Harlem  River,  there  would  have 
been  some  difficulties  attending  launching,  but,  in  any 
event,  the  method  used  was  thought  to  be  better,  and 
proved  to  be  practical  and  very  satisfactory. 

The  method  of  depositing  the  concrete  around  the  out- 
side of  the  tubes,  and  tests  showing  the  good  quality  of 
concrete  so  deposited,  were  fully  described  in  ENGINEER- 
ING NEWS,  Mar.  17,  1910;  the  method  and  plant  used  on 
the  Harlem  River  was  almost  exactly  the  same  with  one 
important  improvement  in  the  control  of  the  tremies. 
The  tremies  are  so  arranged  that  they  can  be  raised  or 
lowered  to  accelerate  or  retard  the  flow  of  the  concrete. 
At  the  head  of  each  tremie  and  attached  to  it,  is  a  plat- 
form on  which  stands  the  man  who  controls  it.  Individ- 
ual hoists  were  provided  for  each  tremie,  controlled  by  a 
continuous  rope  passing  by  the  platform,  so  that  at  any 
position  of  this  latter  the  rope  could  be  reached  by  the 
man,  and  the  raising  or  lowering  of  each  separate  tremie 
made  almost  instantly  and  as  required. 

At  the  Detroit  River  a  steel  grillage  embedded  in  con- 
crete was  placed  in  the  bottom  of  the  trench  at  the  joints 
between  each  section,  but  at  the  Harlem  River  timber 
bents  were  driven.  There  were  4  to  6  bents  at  each  joint ; 
they  were  framed  on  shore  and  driven  by  two  piledrivers, 
moored  facing  each  other  with  long  followers  to  reach  to 
the  necessary  depth.  On  the  first  section  the  bents  were 
driven  an  inch  or  two  low  so  that  the  tubes  might  be 
blocked  up;  it  was  found,  however,  that  such  good  con- 
trol was  possible  that  they  were  afterwards  driven  almost 
exactly  to  grade. 

The  method  of  sinking  the  tubes  is  very  simple;  12-in. 
valves  are  opened  in  the  bottom  of  the  bulkheads  in  the 
two  outside  tubes,  allowing  these  latter  to  fill  gradually 
with  water;  the  two  inner  tubes  are  entirely  open.  The 
rate  of  sinking  after  the  tubes  are  half  full  is  controlled 
by  air  valves  at  the  top  of  the  main  tube,  if  necessary. 
There  is  apparently  no  difficulty  in  keeping  them  level, 
but  to  aid  in  this  two  cross  bulkheads  are  provided, 
reaching  half-way  down  from  the  top,  providing  three 
sections  from  which,  after  the  tubes  are  half  full,  the  air 
escapes  and,  consequently,  the  amount  of  water  enter- 
ing can  be  controlled  by  opening  or  closing  the  air  valves. 
The  tendency  of  either  end  or  corner  to  get  out  of  level 
was,  therefore,  easily  controlled.  As  the  tubes  become 
completely  filled,  the  flotation  is  carried  by  the  four  cyl- 
inders on  top,  which  are  in  turn  gradually  partially  filled 
and  the  excess  weight,  which  is  not  great,  is  taken  by 
derrick  boats  moored  on  either  side  during  the  sinking. 
The  method  of  control  of  position  is  shown  in  the  dia- 
gram, Fig.  79. 

Some  interesting  statistics  are  as  follows : 

Weight  of  steel  per  lin.ft.  of  structure 5600  Ib. 

Amount  of  exterior  concrete  per  lin.ft.  of  structure  30.0  cu.yd. 
Amount  of  interior  concrete  per  lin.ft.  of  structure  11.6  cu.vd. 
Maximum  depth  M.H.W.  to  subgrade 57.2  ft. 

The  weight  of  the  structure  equipped  for  sinking,  with 
masts,  bulkheads,  sheeting,  buoyancy  cylinders,  etc.,  com- 
plete is  646  tons. 

Buoyancy  of  four  cylinders   (on  top)    722   tons 

Excess   buoyancy   four   cylinders    76  tons 

requiring  19  tons  of  water  in  each  to  overcome  buoyancy. 
One  hour  is  required  to  fill  the  structure  with  water. 


Cross  passages  are  provided  between  the  tubes  at  ap- 
proximately every  50  ft.,  in  the  outer  partitions,  and 
two  openings  in  the  whole  length  of  the  tubes  through 
the  center  partition.  There  is  a  sump  in  each  tube 
at  the  lowest  point,  universal-joint  cast-iron  pipe  be- 
ing used  for  discharge.  Access  shafts — one  for  each 
tube — are  provided  near  the  ends  of  the  end  sec- 
tions, by  which  access  can  be  obtained  to  the  inter- 
ior of  the  tubes  after  the  outside  concreting  is  completed. 
The  ends  of  the  last  sections  are  fitted  with  slots  (two 
angles)  to  take  the  sheeting  of  the  coffer-dams  which  are 
built  to  connect  them  with  the  land  sections  built  in  open 
cut.  The  connecting  coffer-dam  is  of  a  single  row  of 
steel  sheet  piling;  clay  being  dumped  on  the  outside,  if 
necessary,  to  make  it  tight. 

ROOF  SHIELDS 

Just  north  of  the  Harlem  River  the  westerly  branch  of 
the  subway  passes  under  the  main  line  of  the  N.  Y.  C.  & 
H.  R.  R.R.,  which  at  this  point  carries  all  the  traffic  from 
its  own  lines  as  well  as  from  those  of  the  N.  Y.,  X.  H. 
&  H.  R.R.,  to  and  from  the  Grand  Central  Terminal.  The 
railway  has  five  tracks  and  is  carried  on  a  fill  between 
high  masonry  retaining-walls.  The  base  of  rail  of  the 
subway  line  is  to  be  between  40  and  50  ft.  below  that  of 
the  railway  above. 

It  was  at  first  thought  that  this  work  might  be  car-ied 
out  in  open  cut,  carrying  the  railroad  on  timber  false- 
work, but  the  acute  angle  of  the  crossing,  depth  and 
character  of  material  would  have  made  this  a  somewhat 
hazardous  undertaking,  and  it  was  finally  decided  to  adopt 
the  method  shown  in  the  accompanying  drawings. 

Timbered  drifts  have  been  driven,  as  shown  in  Fig.  80, 
the  center  one,  as  will  be  noted,  being  considerably  higher 
than  the  other  two  on  the  outsides.  The  material  en- 
countered has  been  mostly  rock,  but  the  work  was  ren- 
dered quite  difficult  in  parts  by  reason  of  the  fact  that 
the  top  of  the  rock  was  just  below  the  top  of  the  drifts, 
requiring  the  support  of  the  earth  overhead  and  blasting 
of  the  rock  below. 

In  these  drifts  the  side  and  center  walls  are  to  be 
built  of  concrete  and  then  the  balance  of  the  excavation 
is  to  be  taken  out  under  the  protection  of  the  double,  seg- 
mental  roof  shields,  details  of  which  are  shown  in  the 
drawings,  Fig.  81.  These  shields,  as  will  be  seen,  are 
quite  unique  in  design  and  form.  It  is  intended  to  work 
each  independently  of  the  other,  shoving  one  at  a  time, 
but,  of  course,  not  to  be  the  extent  of  one  entirely  clearing 
the  other,  as  they  necessarily  react  on  each  other  to  take 
up  the  side  thrust. 

The  writer  is  especially  indebted  to  Mr.  Olaf  Hoff,  of 
the  firm  of  McMullen  &  Hoff,  the  contractors  for  this 
work,  for  the  above  information,  for  the  plans  and  details 
of  these  shields,  and  of  the  Harlem  River  tubes,  he  being 
principally  responsible  for  the  design  and  execution  of 
this  portion  of  the  work. 

THE  EAST  RIVER  TUNNELS 

The  additional  connections  between  the  new  lines  in 
Brooklyn  and  those  in  Manhattan  are  to  be  by  means 
of  two  pairs  of  tunnels  under  the  lower  end  of  the  East 
River,  as  described  in  ENGINEERING  NEWS,  Apr.  30,  1914. 
The  contracts  for  all  four  tunnels  were  recently  awarded 
to  the  Flinn-O'Rourke  Co.  for  a  total  amount  of  about 
$12,500,000,  and  work  was  actually  started  about  Nov.  1 
on  the  sinking  of  the  shafts. 


[61] 


The  tunnels  are  to  be  driven  by  the  shield  method  and 
there  are  two  novel  features  which  are  to  be  tried  to  which 
attention  may  be  called  at  this  time. 

In  several  places  the  roofs  of  the  tunnels  are  quite  close 
to  the  river  bed,  so  that  additional  cover  must  be  provided. 
Owing  to  the  swiftness  of  the  tidal  current  at  this  point 
and  its  scouring  action,  the  problem  of  retaining  a  clay 
blanket  in  place  according  to  the  method  heretofore  used 
in  East  River  tunneling  seemed  to  be  one  of  some  diffi- 
culty. The  method  proposed,  however,  will  not  only  prob- 
ably retain  the  clay,  but  by  placing  the  material  at  this 
time  (November,  1914)  it  will  settle  well  into  position 
and  become  nearly  impervious,  by  the  time  the  tunnels  are 
driven.  A  comparatively  narrow,  thin  blanket  of  clay  is 


Bottom  of/      /     N 
River  " 


(  0      C  ) 

V — ^---Tunnels  X^^S 


FIG.  82.  METHOD  OF  COVERING  RIVEE  BOTTOM  OVER 
EAST  RIVER  TUNNELS 

first  deposited  on  a  line  on  each  side  of  the  location  of  the 
tunnels.  Rock  from  any  of  the  numerous  excavations  al- 
ways going  on  in  and  around  New  York  is  dumped  on 
top  of  this  and  a  clay  blanket  varying  in  thickness  from  5 
to  15  ft.  is  then  dumped  between  these  piles  of  rock,  and 
is  finally  covered  with  other  rock,  as  shown  in  the  sketch 
Fig.  82.  This  blanket  will  be  approximately  125  ft.  in 
width  over  all.  It  is  believed  this  clay  blanket  will  stay 
in  position  and  effect  the  desired  purpose.  The  contrac- 
tors have  been  fortunate  in  being  able  to  obtain  an  excel- 
lent grade  of  clay  from  dredging  in  progress  on  the  Hud- 
son River,  near  Edgewater,  N.  J.,  which  ordinarily  would 
have  to  be  towed  to  sea  for  disposal. 

The  second  feature  is  a  method  of  filling  the  annular 
space  around  the  outside  of  the  tunnel  left  behind  the  tail 
of  the  shield,  when  the  latter  is  shoved  ahead.  The  outside 
diameter  of  shields  used  for  tunneling  is  usually  from  6 
to  8  in.  greater  than  the  outside  diameter  of  the  tunnel, 


this  leaving  a  space  of  3  or  4  in.  all  around  to  be  filled 
by  the  movement  of  the  surrounding  material  or  in  some 
other  manner,  as  the  shield  is  forced  forward.  This  move- 
ment, while  not  always  of  importance,  does  tend  to  pro- 
duce distortion  to  the  cast-iron  lining  and  to  settlement 
of  the  ground  above  the  tunnel,  which  latter  may  be  un- 
desirable by  reason  of  possible  damage  to  overhead  struc- 
tures, as  in  the  street  approaches  to  these  East  River  tun- 
nels, and  as  happened  in  Joralemon  St.,  Brooklyn,  dur- 
ing the  construction  of  the  Battery  tunnel  for  the  first 
subway  line  to  Brooklyn.  In  such  material  as  that  under 
the  East  River,  which  is  mostly  sand  and  gravel  and  es- 
pecially with  the  tunnels  so  near  the  surface,  any  disturb- 
ance of  the  ground  above  the  tunnels,  even  in  the  river 
with  no  buildings  above,  is  undesirable.  Its  prevention 
will  probably  also  tend  to  lessen  the  waste  from  escaping 
air. 

The  shield  is  to  be  built  with  a  double  skin  of  ^-in. 
plates  separated  by  a  space  of  1*4  in.  The  clearance  be- 
tween the  shield  and  the  tunnel  is  %  in.  The  two  skins 
are  separated  by  I%x3%-jn.  separators.  Eight  rectan- 
gular pipes  ygxl1/^  in.  inside,  %  in.  thick,  project  through 
the  back  of  the  shield,  ana  gravel  similar  to  that  used  for 
roofing  purposes,  is  blown  through  these  pipes  by  air 
pressure  to  fill  the  space  as  the  shield  is  shoved  ahead. 

Experiments  on  a  small  scale  have  already  been  made 
which  show  fairly  conclusively  the  feasibility  and  practic- 
ability of  this  method  for  preventing  any  movement  of  the 
surrounding  material  into  the  space  left  by  the  shield, 
but  a  full-size  shield  is  now  nearing  completion  with 
which  final  tests  are  to  be  made  with  the  complete  appar- 
atus. 

If  the  two  improvements  above  described  succeed  in  any 
marked  degree  in  overcoming  the  difficulties  usually  ex- 
perienced in  tunneling  through  water-bearing  loose  sand 
and  gravel,  with  light  cover,  by  reason  of  blowouts,  the 
generally  quite  considerable  loss  of  air,  consequent  heat- 
ing of  the  tunnel,  and  the  settlement  of  the  ground  above, 
they  must  be  considered  as  a  distinct  advance  in  the  art 
of  subaqueous  tunneling. 

The  writer  is  indebted  to  John  F.  O'Rourke  and 
W.  Gray,  who  have  developed  these  methods,  for  the 
above  information. 


"   I 


The  total  amount  of  concrete  to  be  used  on  the  whole 
of  the  subway  construction  is,  of  course,  quite  large,  but 
speaking  generally  there  is  little  of  the  work  where  there 
are  large  masses,  or  where  a  great  deal  is  required  at  one 
time,  so  that  there  are  no  elaborate  plants  for  turning 
it  out  in  large  quantities.  Three  general  methods  are 
used,  a  central  mixing  plant  of  comparatively  small  ca- 
pacity, the  material  being  hauled  in  motor  trucks  to  the 
point  of  delivery  into  the  forms,  a  portable  or  movable 
mixer  at  the  site,  and  hand  mixing  on  the  planking  of 
the  roadway  immediately  over  the  work.  This  latter 
seems  an  anomaly  in  these  days  of  the  very  general  iise  of 
machinery;  but  in  reality  on  account  of  the  relatively 
small  amount  of  material  usually  required  to  fill  a  con- 
siderable space  in  the  forms,  this  latter  method  in  many 
cases  seems  to  be  quite  as  -economical  and  efficacious  as 
any  of  the  others. 

CONCRETING  PLANTS 

The  few  specific  plants  and  methods  described  below 
are  fairly  typical.  On  Sec.  8.  10  and  11.  Lexington  Ave., 
the  concrete  was  all  mixed  dry  in  two  1-yd.  batch  mixers, 
at  the  iMith  St.  Dock  on  the  East  Eiver,  from  whence  it 
was  hauled  in  wagons  holding  about  3  cu.yd.  to  the  point 
at  which  it  was  to  be  used.  The  use  of  horse-drawn 
wagons  prevented  the  addition  of  the  water  before  haul- 
ing on  account  of  the  length  of  time  required  to  make 
the  trip.  It  was  usually  dumped  on  the  street  decking, 
water  added,  and  the  mixture  shoveled  into  chutes  directly 
into  the  work  in  the  cut-and-cover  sections,  or  delivered 
down  the  shafts  into  1-yd.  cars  for  the  tunnels.  These 
cars  were  hauled  to  the  point  where  the  material  was  to 
be  used  and  there  dumped  directly  when  the  material 
was  placed  in  the  floors  or  footings  of  the  walls,  or  hauled 
up  a  short  section  of  movable  inclined  track  to  a  platform 
at  about  the  level  of  the  springing  line,  where  they  were 


dumped  and  the  material  shoveled  into  the  forms  for  the 
arches  and  sidewalls. 

In  one  case  in  the  tunnels  on  Sec.  9,  a  timber  platform 
was  suspended  at  about  the  springing-line  level  from  eye- 
bolts,  built  into  the  concrete  arch.  The  concrete  was  de- 
livered into  cars  at  the  level  of  this  platform  at  the  shaft, 
and  pushed  along  a  track  on  it  to  the  point  where  it  was 
to  be  used.  This  required  the  permanent  use  of  a  consid- 
erable quantity  of  tiinber,  however,  and  after  a  length  of 
some  300  or  400  ft.  had  been  built  this  way,  a  small  trav- 
eler with  an  elevator  was  built  to  hoist  the  cars  from 
subgrade  level  to  the  springing  line.  This  was  in  a  sec- 


FIG.  83.     LAYOUT  OF  PLANT  FOR  PLACING  CONCRETE  IN 
DOUBLE-TBACK  TUNNELS,  LEXINGTON  AVE. 

tion  where  the  rock  required  no  support  so  that  the  whole 
section  was  clear.  The  platform  of  the  traveler  at  the 
springing  line  reached  across  both  tunnels  and  was  located 
in  the  clear  excavation  ahead  of  the  forms.  The  footings 
of  the  sidewalls  were  built  first  and  kept  ahead,  and  tracks 
for  both  the  traveler  and  the  forms  were  laid  on  them. 
The  track  in  one  tunnel  was  used  for  concrete  cars,  and 
in  the  other  for  the  muck  cars.  The 'concrete  cars  were 
brought  in  under  the  traveler,  hoisted  by  the  elevator 
to  the  upper  platform,  from  which  both  arches  could  be 
reached.  The  general  layout  is  shown  in  the  sketch, 
Fig.  83. 

Wooden  and  steel  forms  have  both  been  used  on  all 
four  of  these  sections;  the  general  opinion  seems  to  be 
that  where  there  is  a  length  of  say  over  300  or  400  ft.  of 


FIG.  84.     PNEUMATIC  CONCRETE  MIXING  AND    CONVEYING  PLANT  FOR  HARLEM  RIVER  TUNNELS 

.'Mixer  on   left,  bins  on  right.) 

[63] 


FIG.  85.     VIEWS  OF  QUEENS  BOULEVARD  KEINFORCED-CONCRETE  VIADUCT  DURING  CONSTRUCTION 

(A)   Columns  completed.      (B)   Foundation  for  columns.      (C)    Columns   showing   forms.      (D)    Abutment    at   New   York   end. 


lining  all  of  the  same  section,  steel  forms  of  the  Blaw 
type  are  cheaper  and  quite  satisfactory.  The  Blaw  forms 
keep  their  shape  quite  well  under  ordinary  conditions; 
but  they  could  not  be  used  to  advantage  in  the  sections 
where  continuous  support  of  the  ground  by  posts  was 
necessary,  and,  of  course,  not  at  all  in  sections  where  posts 
had  to  be  left  in  while  the  lining  was  placed  and  only 
removed  after  the  arch  had  taken  the  weight. 

On  Sec.  9  motor  trucks  were  used  for  the  concrete,  thus 
permitting  the  complete  mixing  with  water  at  the  dock, 
which  was  possible  by  reason  of  the  rapid  means  of 
transit  these  trucks  provided. 

On  Sec.  12  a  %-yd.  batch  mixer  was  used,  set  up  along 
the  side  of  the  street  and  moved  along  as  the  work  pro- 
gressed, the  concrete  being  mixed  at  the  point  where  used. 
Blaw  forms  were  used,  but  on  account  of  the  continually 
varying  dimensions  of  structure,  were  found  to  be  not 
as  easily  adaptable  as  on  work  where  they  could  be  used 
over  and  over  again  without  change. 

On  Sec.  13  the  concrete-mixing  plant  is  located  at  the 
dock  at  the  foot  of  125th  St.,  the  average  haul  to  the  work 
being  about  half  a  mile.  A  2-yd.  batch  mixer  is  used,  ar- 
ranged with  the  necessary  bins,  etc.,  for  convenient  feed- 
ing of  the  materials,  and  so  as  to  deliver  the  mixed  con- 
crete about  10  ft.  above  the  ground.  Two  motor  trucks 
with  self-tipping  bodies  holding  4  yd.  each  are  used  for 
hauling  the  mixed  concrete  to  the  work.  The  latter  is 
mixed  fairly  wet  at  the  mixer,  and  a  little  more  water  is 
added  for  cleaning  as  it  is  dumped;  an  air  pipe  is  kept 
in  readiness  to  be  used  if  necessary,  to  help  get  it  out  and 
clean  the  wagon.  This  is  just  a  short  length  of  5  or  6  ft. 
of  inch  pipe  at  the  end  of  a  hose,  capped  at  the  end  and 


with  small  holes  bored  in  it.  It  can  be  pushed  into 
any  mass  which  has  shaken  down  so  as  to  become  a  little 
tight  and  so  start  it.  At  the  work  when  a  section  is  ready 
for  concrete,  holes  are  cut  in  the  wooden  street  decking  at 
suitable  intervals  and  a  line  of  8-in.  conical  sheet-metal 
spouts  in  5-ft.  sections  is  hung  to  lead  from  the  hole  in 
the  decking  to  the  forms.  The  sections  are  slung  one 
below  the  other  by  chains.  Over  the  hole  in  the  decking 
is  placed  a  wooden  hopper  7x13  ft.  and  2  ft.  deep,  into 
which  the  truck  dumps  its  load  and  is  away  in  about  two 
minutes. 

The  hoppers  are  on  skids  and  are  not  connected  with 
the  spout  or  the  decking.  They  are  moved  by  hitching 
them  by  a  chain  to  a  truck.  The  trucks  make  a  round 
trip  from  the  mixer  to  the  place  of  dumping  and  return 
to  the  mixer  in  from  15  to  20  min. 

On  Sec.  15  there  is  a  central  mixing  plant  with  a  1-yd. 
batch  mixer.  The  concrete  is  carried  in  1-yd.  double- 
hinged  bottom-dumping  buckets,  two  of  which  are  mount- 
ed on  a  flat-car ;  two  cars  are  hauled  together  by  a  dinkey 
on  3-ft.  gage  track.  The  cars  are  arranged  on  the  flat- 
car  frame  so  that  they  can  be  dumped  through  it  with- 
out removing  them.  On  this  section  the  work  is  only 
partially  decked  over  and  the  track  is  laid  over  the  open 
trench.  The  cars  with  the  buckets  are  run  to  the  point 
where  the  work  is  being  done,  spotted  over  the  top  of  a 
chute  and  hopper  and  each  bucket  dumped  in  succession 
into  it. 

For  the  Harlem  Tubes,  the  outer  concrete,  as  has  al- 
ready been  described,  was  mixed  by  machinery  on  a  lighter 
and  deposited  by  means  of  tremies.  For  the  lining  of  the 
inside  of  the  tubes,  the  compressed  air  or  pneumatic  sys- 


[64] 


- 

, 

Half    Elevation 


a'- >k- 0-- — 


Half  Section    C-C 


|t»Vf     e' 


FIG.  86.  DETAILS 
OF  DESIGN  OF 
TYPICAL 
SPAN,  QUEENS 
Bou  LEVARD 
VIADUCT 


Section  D-D 


tern  controlled  by  the  Chicago  Concrete  Placing  Co.  was 
tried  at  the  northerly  end  for  a  part  of  the  section. 

The  views  in  Fig.  84  show  the  general  layout  of 
this  plant,  which  it  was  expected  to  use  for  the  lining 
of  half  the  length  of  the  tubes.  It  is  installed  on  a  plat- 
form built  over  the  water.  The  materials  are  fed  in 
the  proper  proportions  from  the  overhead  bins  into  the 
cylinder  of  the  machine  in  half-yard  batches.  Water  is 
added,  from  a  pipe  leading  into  the  top  of  the  cylinder  at 
the  same  time  as  the  dry  material  enters  from  above,  the 
quantity  being  carefully  measured,  as  it  is  of  some  impor- 
tance to  get  the  proper  consistency.  An  air  valve  is  then 
opened,  and  used  as  a  blower  to  clean  the  gasket  forming 
the  seat  of  the  top  door  which  is  then  closed.  Air  is  then 
admitted  from  the  second  valve  over  the  top  of  the  mix- 
ture to  seal  the  top  door,  and  apply  pressure  behind  the 
mass,  then  the  lower  air  valve  opening  into  the  elbow  in 
the  pipe  just  below  the  discharge  at  the  bottom  of  the  cyl- 
inder is  opened,  to  loosen  up  the  material  as  it  feeds  into 
the  pipe,  and  both  these  last  two  valves  are  kept  open  until 
the  drop  in  the  pressure  shows  that  the  batch  has  been 
discharged  from  the  end  of  the  pipe. 

Normally,  very  little,  if  any,  trouble  has  been  exper- 
ienced in  discharging  the  concrete  at  distances  up  to 
500  ft.,  for  which  an  air  pressure  of  about  80  Ib.  is  used, 
and  the  material  has  been  carried  over  800  ft.  in  the 
work,  but  to  do  this  the  air  pressure  had  to  be  increased 
to  100  Ib.  and  there  were  some  few  difficulties  which, 
however,  should  be  overcome  in  similar  work  as  the  men 
get  used  to  the  apparatus. 

On  leaving  the  main  cylinder  the  pipe  runs  hori- 
zontally for  25  or  30  ft.,  then  drops  vertically  50  ft. 
or  so  to  the  bottom  of  the  tunnels,  and  then  along  the 


floor  to  the  point  of  discharge.  Only 
the  bottom  of  the  tunnels  was  put 
in  by  this  method,  which  for  this  kind 
of  work  probably  has  few  advantages 
jver  any  other  method.  In  placing 
the  sides  and  arch,  however,  which  it 
was  expected  to  be  able  to  accomplish 
at  one  operation,  the  method  should 
have  advantages  if  successful,  as  it 
would  avoid  lifting  the  cars  or  buckets 
up  onto  a  platform  and  the  necessary 
shoveling  into  the  forms. 

As  many  as   40   batches    (20  yd.) 
have  been  placed  in  one  hour  but  the 


,--** 


H_  Base  of  Ha// 

InfermectiarfeSfrf^J?, 


Section  C-D      i 

Enlarged          -< f' 

j { Section    ttirough     Station 


•/TiteS 

'.-'  ~.~.~'  ".-' 

55' Span 


0.169.36 


—27'—----       ^<     44' 


StreefSurface 


Section    ttirough    Abutment 

FIG.  87.     SECTION  THROUGH  STATION  AND  DETAILS  OF 
ABUTMENT.  QUEENS  BOULEVARD  VIADUCT 

average  for  an  8-hr,  shift  is  not  over  65  to  70  yd.,  due  to 
delays  for  shifting  forms,  shifting  the  pipe,  etc.  The 
work  is  being  prosecuted  continuously  day  and  night, 
three  8-hr,  shifts  being  worked. 


[65] 


REINFORCED-CONCRETE  ELEVATED  RAILWAY 

A  part  of  the  elevated  structure  to  be  built  between  the 
Queensboro  Bridge  Plaza  in  Long  Island  City  and  Co- 
rona is  of  reinforced  concrete.  This  section,  which  is 
4271  ft.  in  length,  is  that  which  traverses  Queens  Boule- 
vard, a  parkway  200  ft.  in  width  and  one  of  the  main  ar- 
teries of  travel  from  New  York  City  out  into  Long  Island. 
It  was  desired  to  make  this  an  ornamental  structure,  and 
the  drawing  reproduced  in  the  first  of  this  series  of  ar- 
ticles (Fig.  3)  gives  an  idea  of  the  appearance  of  the 
completed  structure. 

The  views  in  Fig.  85  show  the  construction  of  the  col- 
umn foundations,  the  columns  and  the  abutment  at  the 
New  York  end.  A  longitudinal  section  on  the  center  line 
of  the  structure  through  the  end  abutment,  is  shown  in 
Fig.  87,  and  longitudinal  and  cross-sections  of  the  main 
viaduct  arches  and  piers  in  Fig.  86.  The  type  of  stations, 
of  which  there  are  three  in  this  reinforced-concrete  sec- 
tion, is  shown  in  the  perspective  drawing  already  referred 
to  and  the  details,  and  particularly  the  overhang  for  the 
platforms,  in  Fig.  87. 

As  will  be  seen  by  the  photographs,  the  columns  were 
first  built  up  to  a  point  slightly  above  the  springing  line 
of  the  arches,  then  the  heavy  cross-girders  at  each  bent 
were  placed  in  position,  after  which  the  arches  and  par- 
apet walls  were  poured. 

A  central  mixing  plant  for  the  concrete  was  estab- 
lished near  the  New  York  end  with  a  1-yd.  batch  mixer 
operated  by  an  electric  motor  with  chain  drive.  The  con- 
crete was  distributed  from  this  point  by  dinkeys  and 
trains  of  small  four-wheel  flat-cars,  each  carrying  a  single 
1-yd.  double-hinged,  bottom-dumping  bucket.  A  stand- 
ard-gage railroad  track  was  first  laid  the  whole  length 
of  the  work,  between  the  two  rows  of  columns.  This  was 
used  for  the  operation  of  two  15-ton  locomotive  cranes, 


FIG.  88.     CONCRETE  BUCKETS  ABOUT  TO  BE  LOADED 

and  for  the  distribution  of  material.  The  cranes  were 
used  for  various  purposes  in  place  of  derricks,  and  for 
handling  the  forms  and  the  concrete  in  the  buckets,  the 
latter  being  picked  up  off  the  cars  and  dumped  directly 
into  place.  The  concrete  train  and  dinkeys  were  operated 
on  the  2-ft.  gage  track  laid  in  the  center  of  the  standard 
gage,  during  the  construction  of  the  piers,  five  cars  being 
used  in  each  train. 

As  soon  as  the  construction  of  the  columns  was  fin- 
ished, the  cross-girders,  which  weighed  27  tons  each,  were 


placed  on  top  of  them,  being  handled  by  a  derrick  car,  as 
they  were  rather  too  heavy  for  the  locomotive  cranes. 

For  the  construction  of  the  arches,  a  standard-gage 
track  for  the  two  cranes  was  laid  just  outside  the  westerly 
row  of  columns,  and  a  double-track  narrow-gage  line  for 
the  concrete  train  outside  of  this.  When  concreting  from 
1000  to  2000  ft.  away  from  the  mixer,  three  trains  of 


FIG.  89.    LIFTING  CONCRETE  BUCKETS  INTO  PLACE, 
QUEENS  BOULEVARD  VIADUCT 

five  cars  each  were  used  to  distribute  the  concrete.  Clean, 
rounded  gravel  of  fairly  uniform  size,  graded  from  % 
to  iy2  in.,  is  used  for  the  aggregate,  making  a  mixture 
which  will  probably  give  good  results  for  the  proposed 
hammered  finish  for  the  surface. 

It  will  be  noted  from  Fig.  86  that  the  arches  curve 
both  ways,  giving  somewhat  the  effect  of  a  dome.  The 
central  third  of  each  arch  extending  right  across  the 
structure,  together  with  a  part  of  the  two  side  parapet 
walls,  was  first  poured,  then  when  that  had  set,  the  two 
sides  between  the  central  third  and  the  cross-girders  were 
poured  together.  The  forms  are  left  in  place  28  days  and 
it  is  expected  to  use  eacli  set  of  forms  three  or  four  times. 

For  pouring  the  arches,  hoppers  are  erected  above  them 
into  which  the  buckets  (Fig.  88),  lifted  off  the  cars  by 
the  cranes,  are  dumped  (Fig.  89).  The  concrete  is  then 
distributed  from  the  hopper  by  short  chutes  as  required. 
For  the  central  section  one  hopper  is  used,  for  the  end 
sections  two  hoppers,  one  for  each;  the  central  section  is 
placed  without  top  forms,  but  these  latter  are  required 
for  the  steeper  slopes  of  the  two  end  sections. 

It  is  proposed  to  hammer-finish  all  exposed  concrete 
faces,  ilsing  a  patent-hammer  for  all  plain  surfaces  and 
a  bush-hammer  for  recessed  panels.  The  ends  of  the 
cross-girders  on  top  of  the  columns  and  the  longitud- 
inal panels  of  the  parapet  walls  are  to  be  faced  with  col- 
ored ornamental  tiling. 


[66] 


Design  of  Steel  Elevated  Railways 


The  new  rapid-transit  lines  now  under  construction  in 
New  York  City  include  144  miles  of  subway  and  106 
miles  of  elevated  track  to  be  built  by  the  city,  and  also 
third-tracking  and  extensions  of  their  present  elevated 
lines  by  the  operating  companies  totaling  67  miles  of 
track.  Plans  for  the  city-built  lines  are  made  by  the  Pub- 
lic Service  Commission,  while  plans  for  the  extensions  of 
the  present  elevated  lines  are  being  made  by  the  compan- 
ies subject  to  the  approval  of  the  commission.  In  this 
chapter  some  features  of  the  design  of  the  city-built  ele- 
vated lines  will  be  considered. 

OPEN-FLOOR  OR  SOLID-FLOOR  CONSTRUCTION 
A  subway  is  preferable  to  an  elevated  line  from  the 
standpoint  of  the  property  owners  along  the  route,  and  a 
general  policy  of  not  constructing  elevated  lines  in  the 
central  congested  districts  has  been  followed.  On  the 
other  hand,  the  cost  of  a  subway  is  so  great  that,  with  the 
city's  present  financial  condition,  a  universal  subway  sys- 
tem is  out  of  the  question.  The  program  therefore  pro- 
vides trunk-line  subways  through  the  central  districts  of 
Manhattan  and  Brooklyn,  with  elevated  feeders  in  the 
outlying  districts. 

When  the  Triborough  system  was  under  consideration 
in  1910  it  was  proposed  to  build  elevated  extensions  or 
feeders  with  ballasted  track  on  a  solid  concrete  floor  to 
reduce  the  noise  to  a  minimum,  thereby  reducing  some- 
what the  objections  to  the  elevated  lines.  When  the  pres- 
ent dual-system  contracts  were  prepared  the  city's  finan- 
cial condition  made  it  imperative  that  the  feeders  be  built 
as  cheaply  as  possible.  The  relative  cost  of  subway  and 
elevated  lines  with  ballasted  floor  and  with  open  floor  for 
the  106  miles  of  proposed  elevated  tracks  are  as  follows: 

COST  OF  SUBWAY  AND  ELEVATED  STRUCTURE 

Per  Lin.Ft.  of  Structure        Total 

Three-track    subway $300  to  $500  $63,000.000 

to  105,000,000 

Three-track   elevated  1  Solid    floor.          $200  42,000,000 

(  Open   floor.  125  26,000,000 

The  open-floor  construction  would  cost  about  $16,000,000 
less  than  the  solid-floor  and  from  $37,000,000  to  $69,000,- 
000  less  than  the  subway.  It  is  therefore  evident  why 
open-floor  elevated  construction  was  used  for  the  feeders 
in  outlying  distri.  t-. 

TYPE  OF  BENT 

The  elevated  lines  consist  largely  of  a  three-track  con- 
struction, providing  two  tracks  for  local  service  and  a 
center  track  for  rush-hour  express  service  in  the  direction 
of  the  maximum  traffic  (returning  the  express  trains 
empty  over  the  local  track).  In  general  a  two-column 
bent  was  found  to  be  most  satisfactory  and  most  eco- 
nomical; it  has  been  adopted  uniformly  except  in  special 
cases,  such  as  at  stations,  where  the  structure  is  widened 
to  such  an  extent  that  three  or  four  columns  are  neces- 
sary. 

COLUMNS  IN  ROADWAY 

AYith  the  two-column  bent  there  are  in  general  two 
practicable  positions  for  the  columns — namely,  in  the 
roadway  and  on  the  sidewalk  near  the  curb.  As  any  ob- 
struction in  the  roadway  is  always  a  source  of  danger  to 
traffic,  it  is  desirable  to  keep  the  roadway  clear  of  columns 
as  far  as  possible.  On  the  other  hand,  in  wide  streets  a  ma- 
terial saving  in  cost  is  effected  by  placing  the  columns  in 
the  roadway.  Furthermore,  the  appearance  is  largely  im- 

[67] 


proved  by  eliminating  wherever  possible  the  long  trans- 
verse girders  projecting  beyond  the  longitudinal  stringers. 
The  cost,  appearance  and  obstruction  to  street  traffic  were 
therefore  factors  in  determining  the  column  location.  The 
widths  of  roadway  for  various  street  widths  have  been 
fixed  by  resolution  of  the  Board  of  Estimate  and  Appor- 
tionment as  follows : 


Street   -width,    feet 

Roadway   width,   feet. 


100 
60 


80 
44 


70 
36 


60 
30 


With  a  60-ft.  roadway  it  was  not  considered  practicable 
to  place  the  columns  on  the  sidewalk,  as  the  cross-girders 
would  be  over  63  ft.  long  and  would  project  16.5  ft.  on 
each  side  beyond  the  outside  longitudinal  stringer.  With 
columns  in  the  roadway  the  exact  location  was  determined 
by  their  relation  to  the  longitudinal  stringer  (affecting 
the  strength,  rigidity,  appearance  and  cost  of  the  struc- 
ture), to  surface-car  tracks,  and  to  the  lines  of  vehicular 
traffic. 

Structurally  it  is  desirable  to  place  the  columns  under 
the  outside  stringer.  AVith  this  construction,  longitudinal 
curved  brackets  can  be  placed  advantageously  on  the  col- 
umn under  the  stringer,  thus  reducing  the  unsupported 
length  of  column,  increasing  the  rigidity  of  the  structure 
and  producing  a  pleasing  appearance..  By  placing  the  col- 
umns between  the  stringers  of  the  outside  tracks  the  sec- 
tion of  the  cross-girder  is  reduced  slightly  and  the  section 
of  the  column  increased  correspondingly,  as  longitudinal 
brackets  are  not  feasible  with  this  construction.  The 
brackets  increase  the  cost  by  $1  to  $1.50  per  foot  of  struc- 
ture; but  this  cost,  other  things  being  equal,  would  be 
warranted  by  the  additional  rigidity  of  the  structure 
and  the  improved  appearance. 

Cars  to  be  operated  by  the  Interborough  Bapid  Transit 
Co.  are  9  ft.  wide,  52  ft.  long  and  36  ft.  c.  to  c.  of  trucks ; 
those  to  be  used  by  the  New  York  Municipal  Eailway 
Corporation  are  10  ft.  wide.  66  ft.  long  and  47  ft.  c.  to  c. 
of  trucks;  all  are  standard-gage.  Stringers  are  spaced 
5  ft.  c.  to  c.,  so  that  practically  all  stress  in  the  ties  except 
direct  compression  is  eliminated.  For  safety  it  is  desirable 
to  have  about  3  ft.  clear  between  cars  on  adjacent  tracks. 
For  Interborough  operation,  however,  the  tracks  were 
spaced  I2y2  ft.  c.  to  c.  on  tangents,  to  provide  additional 
clearance  to  the  through  girders  over  the  station  mezza- 
nines, while  for  the  Municipal  corporation's  operation 
they  were  kept  13  ft.  c.  to  c.  With  the  columns  placed 
under  the  stringers  the  transverse  column  spacing  is 
therefore  30  ft.  and  31  ft.  c.  to  c.  respectively  for  the  two 
companies,  dividing  the  roadway  as  shown  in  Fig.  90. 

Trolley  tracks  are  usually  spaced  about  10  ft.  c.  to  c., 
except  where  a  greater  width  is  required  on  account  of  cen- 
ter poles,  in  which  cases  12^  ft.  and  13  ft.  are  the  most 
common  spacings.  When  an  elevated  structure  is  built 
over  such  a  line  the  poles  are  removed  and  the  trolley 
wires  supported  from  the  structure.  The  tracks  can  then 
be  spaced  10  ft.  For  safety  to  passengers  a  clearance  of 
about  3  ft.  from  the  side  of  the  car  to  the  face  of  the 
column  is  desirable — that  is,  about  7^  ft.  from  the  center 
line  of  track  to  face  of  column  (although  some  lines  are 
now  operated  in  Manhattan  with  only  1  ft.  10  in.  clear). 
With  tracks  spaced  10  ft.,  and  7  ft.  4  in.  clear  from  center 
of  track  to  face  of  a  16-in.  column,  the  minimum  spacing 
of  columns  transverselv  is  26  ft. 


It  is  essential  that  the  columns  be  placed  far  enough 
from  the  curb  to  allow  two  lines  of  vehicles  to  pass  be- 
tween. A  minimum  of  from  15  to  16  ft.  is  required  for 
safety.  To  place  the  columns,  therefore,  for  greatest  safety 
and  efficiency  of  roadway  requires  a  spacing  of  about  26 


-—  /?-—>!  At  Y.Mun.ffy.  Con 
J.RT.Co. 


K5te— -/,?-5-~>|j«.—  /g-(;.—f\  f 
T^'    f T     tJT T    'Af 

w    Tj|r    HI 

wi  i.      JjJsKi     I^KJ 


N.Y.Mun.ffy.Cor: 
I.RT.Co. 


„     Position  of  Column  when  placed  on  Sidewa//r  shown  dotted 

FIG.  90.     Two  POSSIBLE  LOCATIONS  OF  ELEVATED- 
RAILWAY  COLUMNS  IN  STREET 

(Columns  at  curb  and  column  under  outer  stringer) 

ft.,  as  shown  in  Fig.  2.  With  columns  spaced  26  ft.  two 
lines  of  vehicles  can  pass  between  the  curb  and  column  and 
one  line  on  each  car  track,  six  in  all.  With  30-  or  31-ft. 
spacing,  only  one  line  can  safely  pass  between  the  curb 
and  column,  or  four  in  all,  thus  giving  a  66%%  roadway 
efficiency  as  compared  to  the  26-ft.  spacing.  The  conser- 
vation of  the  street  was  deemed  of  greater  importance  than 
the  slight  structural  advantage  of  the  wider  spacing. 
Therefore  26  ft.  was  adopted  as  the  transverse  spacing, 
except  in  a  few  isolated  cases  affected  by  special  local  con- 
ditions. 

COLUMNS  ON  SIDEWALK 

With  roadway  width  44  ft.  or  less,  it  is  evident  that  col- 
umns cannot  advantageously  or  safely  be  placed  in  the 


N.Y.Mun.ffy.Cor. 


-- SO  Roadway    -  —  >| 

FIG.  91.    LOCATION  OF  COLUMNS  ADOPTED  FOR  WIDE 
STREETS 

(On  streets  44  ft.  wide  or  less,  the  columns  are  placed  inside 
the  curb,  with  47  ft.  4  in.  maximum  spacing) 

roadway.  In  order  that  the  columns  may  occupy  as  little 
of  the  sidewalk  space  as  possible,  and  at  the  same  time 
be  protected  from  traffic  by  the  curb,  they  have  been 
placed  uniformly  with  the  center  1  ft.  8  in.  from  the  curb. 
With  44-ft.  roadway  the  transverse  spacing  is  therefore 
47  ft.  4  in. 

LONGITUDINAL  SPACING  OF  COLUMNS 

Except  as  affected  by  local  conditions,  the  longitudinal 
spacing  of  columns  was  determined  by  economy.  Fig. 
92  shows  diagrammatically  the  cost  of  those  items  of  typi- 
cal elevated  construction  between  stations  which  vary  with 
the  span  length,  plotted  for  various  spans  both  for  26  ft. 


and  for  47  ft.  4  in.  transverse  spacing  of  columns.*  An 
inspection  of  this  diagram  shows  that  50  ft.  is  the  eco- 
nomical spacing  and  that  there  is  little  choice  of  other 
span  lengths  from  40  ft.  to  60  ft.,  above  which  point  the 
cost  increases  rapidly  with  the  span  length.  The  50-ft. 
longitudinal  spacing  of  bents  was  therefore  adopted  as  the 
standard. 

At  the  cross-streets  columns  are  spaced  so  that  the  in- 
terference with  traffic  is  the  minimum,  60  ft.  and  longer 
spans  often  being  required  at  these  points.  Uniform  spac- 
ing of  bents  between  streets  is  often  impossible  on  account 


CO 

65 

64- 

63 
£ 

O6* 
061 

f6° 
°59 

"-5S 
|_57 
56 
§55 
<•><* 
53 
52. 

-*&- 

\ 

j& 

\ 

oA 

7 

\ 

^ 

^"^•^ 

—  

r 

K 

/ 

X 

/ 

>/ 

^ 

/>/ 

r 

\ 

^ 

V 

/ 

/ 

X 

— 

^ 

/ 

^^s. 

7 

55         40           45            50           55            60           65           7 

Span     Leng+h,    Fee-r 

FIG.  92.     EFFECT  OF  SPAN  LENGTH  ON  COST  OF  THREE- 
TRACK  ELEVATED  RAILWAY 

(Excludes  track,  stations  and  ducts.  Average  prices  of 
recent  contracts  used  as  follows:  Steel,  $54  per  ton;  cast  iron, 
$48  per  ton;  concrete,  $7  per  cu.yd.;  excavation,  $2  per  cu.yd.; 
paving,  $3  per  sq.yd.) 

of  local  conditions,  varying  block  lengths  and  interfer- 
ence with  surface  and  subsurface  structures.  The  50-ft. 
spacing,  however,  has  been  used  as  far  as  practicable. 

TYPE  OF  CONSTRUCTION 

A  deck  plate-girder  type  of  construction  has  been  used 
exclusively,  except  over  station  mezzanines  and  in  isolated 
cases  where  special  conditions  require  other  construction. 

A  half-through  girder  construction  with  longitudinal 
girders  between  the  tracks  has  been  used  over  the  station 
mezzanines  to  reduce  the  depth  of  construction  so  that 
the  climb  from  street  to  platforms  will  be  a  minimum.  It 
is  uneconomical,  however,  and  if  continuous  would  be  a 
source  of  danger  to  workmen,  as  it  gives  them  less  chance 
to  escape  from  approaching  trains,  particularly  on  the 
center  track. 

A  throiigh-truss  construction  is  evidently  impracticable 
with  columns  placed  in  the  roadway.  With  columns  in 
the  sidewalk  it  is  uneconomical  and  undesirable,  as  it  ob- 
structs light  from  abutting  property  to  a  greater  extent. 

Latticed  stringers  are  from  10  to  15%  lighter  than 
plate-girder  stringers  of  the  same  span.  The  cost  of  fabri- 
cation of  the  latter,  however,  particularly  without  cover- 
plates,  is  about  10%  less  than  of  a  latticed  girder  without 
connection  plates  and  15%  less  than  of  a  latticed  girder 
with  connection  plates.  The  first  cost,  therefore,  is  prac- 
tically the  same  in  either  case.  Depreciation  and  mainte- 
nance costs  of  plate-girder  construction  are  less  than  for 


•These  costs  are  based  on  present  average  prices,  which  are 
unusually  low,  particularly  for  steel,  whose  cost  makes  up 
about  80%  of  the  cost  of  an  elevated  structure  exclusive  of 
track,  signals  and  station  finish. 


[68] 


latticed  girders;  details  are  simpler  and  the  structure  is 
more  rigid.  Plate-girder  stringers  were  therefore  adopted. 

EXPANSION  JOINTS 

On  the  elevated  extensions  of  the  present  subway,  ex- 
pansion joints  were  placed  about  200  ft.  apart,  or  about 
every  fourth  bent.  In  order  to  reduce  to  a  minimum  the 
tension  of  the  top  rivets  of  the  stringer  connection  due  to 
the  combination  of  the  deflection  of  the  stringer  and  con- 
traction, the  distance  between  joints  has  been  reduced  to 


The  expansion  joint  which  has  been  used  exclusively  on 
city-built  lines  is  shown  in  detail  in  Fig.  93.  It  consists 
essentially  of  a  4-in.  half-round  pin  bearing  on  pin-plates 
on  the  stringer  and  sliding  on  a  seat  made  up  of  angles 
and  plates  attached  to  the  cross-girder.  The  thickness 
of  plates  on  both  seat  and  stringer  has  been  made  uniform- 
ly 3  in.  for  all  spans.  The  pin  is  held  in  place  and  the 
stringer  held  in  line  by  small  guide-angles  attached  to 
the  end  stiffeners  on  the  stringer.  The  particular  ad- 
vantages of  this  joint  are  its  simplicity  of  construction 


\l         -     1_ 


,r^~ 

'  \\ 


I 


-:;--   :-    • 

rl    >n                 &  ^Base  of  f?a;/~± 

J  J 

Web   \0'x^f 

n 

4&6x6xg. 

1                                                         "  '  ^ 
Eleva-rion 
—  -  -?»'-—                                              ^ 

Alt  BnrcirKr, 
43£*3£'x* 

except  as.  , 
Jitt-cr/ff?  ?g  _ 


NORMAL  SPAN,  COLUMNS  IN  STREET 
f ,5- 


Section  X-X 


C/fOSS-SECTJOfJ 
SHOWING 


Base  of  Ffcrif 


ftir*  focd  W~  *"?*".  —  i  --  —  • 


Joints  crf- 
dlterncrfe 


fV\ 

;  Sec+i  on   '   4  Section 
D-D         '    EC-C 


Rivets  in  Cols. 
other  Rive+s    g* 


BENT  WITH 

COLUMNS 

IN  STREET 


^  ^s 

COL  UMN  BASE  ~For  hecryY  Loads 


BENT   WITH    COLUMNS    AT    CURB 


FIG.  93.     DETAILS  OF  ELEVATED-EAILWAY  CONSTRUCTION 

(New  city-built  lines  of  dual  rapid-transit  system.  New  York  City) 


about  100  ft.,  or  an  expansion  joint  is  provided  at  alter- 
nate bents.  The  cost  is  thus  slightly  increased,  as  the 
expansion  detail  of  the  stringer  is  slightly  heavier  than  the 
detail  at  the  fixed  end.  and  additional  bracing  is  required. 
It  is  expected,  however,  that  this  increase  in  first  cost 
will  be  more  than  offset  by  a  reduction  in  maintenance 
charges  for  replacing  rivets  in  the  stringer  connections. 


and  ease  of  erection,  its  accessibility  for  painting  and  in- 
spection and  the  certainty  of  a  uniform  bearing  on  the 
seat.  The  connection  of  the  seat  to  the  cross-girder 
has  been  designed  for  the  maximum  shear  combined 
with  the  tension  on  the  rivets  due  to  the  maximum 
moment  with  the  pin  bearing  on  the  extreme  edge  of  the 
seat. 


[69] 


Provision  has  been  made  for  a  contraction  or  expansion 
of  11/2  in.  from  normal  temperature,  which  is  undoubtedly 
slightly  in  excess  of  the  maximum  to  be  expected,  but  al- 
lows for  slight  inaccuracies  in  placing  columns  and  in  the 
milled  length  of  stringers.  It  is  desirable  to  reduce  the 
opening  as  far  as  possible,  in  order  that  the  pin  will  not 
approach  dangerously  near  the  edge  of  the  seat  at  extreme 
low  temperatures. 

This  joint  has  been  used  satisfactorily  on  previous  ele- 
vated extensions  of  the  subway  (contract  1). 

The  elevated  structures  have  been  designed  for  the  fol- 
lowing loads : 

1.  Dead-load.  The  weight  of  track,  including  ties, 
rails,  guard-rails,  service  walk,  signals,  etc.,  estimated  at 


4.  Impact.  With  the  track  resting  directly  on  the 
stringers  the  effect  of  the  impact  from  the  live-load  will 
be  as  great  as,  if  not  greater  than,  on  bridge  spans.  Live- 
load  stresses  (except  for  horizontal  forces)  have  there- 
fore been  increased  for  impact  in  accordance  with 

/  =  125  --  i  V  2000  L  —  L* 

where  7  =  impact  increment  in  per  cent,  and  L  — 
length  in  feet  of  loaded  track  which  produces  the  maxi 
mum  stress  in  the  member.* 

On  a  three-track  line  it  has  been  assumed  that  the  trac- 
tive force  will  at  no  time  exceed  the  effect  of  two  trains 
acting  in  the  same  direction  at  the  same  time.  On  a  two- 
track  line,  where  the  probability  of  trains  on  each  track 
acting  together  is  greater  in  proportion,  provision  has  been 


FIG.  94.     NEW  ELEVATED  STRUCTURE  WITH  COLUMNS  IN  STREET  (WHITE  PLAINS  ROAD,  BRONX  BOROUGH) 


about  400  Ib.  per  lin.ft.  track,  in  addition  to  the  weight 
of  the  structure  itself. 

2.  Live-loads.     A  series  of  concentrations  approximat- 
ing the  weight  of  the  heaviest  equipment  it  is  proposed  to 
operate  on  the  dual  system : 

22,750  lb.— 5  ft.  6  in. — 22,750  Ib.— 29  ft.  11  in. — 30.240  Ib. — 
6  ft.  8  in. — 30,240  lb. — 8  ft.  8  in. — 30,240  lb.— 6  ft.  8  in. — 30,240 
lb. — 29  ft.  11  in. — 22,750  lb. — 5  ft.,  6  in. — 22,750  lb. — 9  ft.  3  in.— 
30,240  lb.— 6  ft.  8  in.— 30,240  lb. 

3.  Horizontal  forces,     (a)  Wind  pressure  of  30  lb.  per 
sq.ft.  on  the  exposed  surface  from  the  top  of  train  to  the 
bottom  of  structure;  (b)  the  sudden  starting  or  stopping 
of  a  500-ft.  train,  estimating  the  coefficient  of  sliding; 
friction  at  10%;    (c)    centrifugal  force  equal  to   0.020 
time  the  product  of  weight  of  moving  cars  and  degree 
of  curve,  the  coefficient  to  be  reduced  by  0.001  per  degree 
for  curvature  between  3°  and  20°. 


made  for  five-sixths  of  the  full  tractive  force.  These  as- 
sumptions, which  are  based  on  the  fact  that  a  considerable 
(though  indeterminable)  part  of  the  tractive  force  is 
transmitted  to  adjacent  spans  through  rails  and  expansion 
joints,  are  believed  to  be  conservative.  No  data  are  avail- 
able to  determine  the  amount  of  distribution,  but  observa- 
tion of  the  present  lines  shows  that  it  is  material.  Further- 
more, the  probability  of  a  train  on  each  track  at  any  span 
starting  or  stopping  at  the  same  time,  so  as  to  exert  full 
tractive  force  on  each  track  in  the  same  direction,  is  re- 
mote. Designed  on  these  assumptions,  the  new  structures, 
at  a  very  small  additional  initial  cost,  will  have  greater 

•For  example,  with  50-ft.  spans,  L  for  the  stringer  is  50 
and  I  =  86%;  for  a  cross-girder  in  which  maximum  stress  is 
produced  with  one  track  loaded  L  =  100  and  I  =  70%;  and 
for  a  cross-girder  in  which  maximum  stress  is  produced  with 
three  tracks  loaded  L  =  300  and  I  =  36%.  Impact  is  added 
similarly  to  column  stresses. 


[70] 


rigidity  against  horizontal  forces  than  the  existing  ele- 
vated  extensions.  This  rigidity,  it  is  believed,  will  in- 
crease the  life  of  the  structure  and  reduce  the  maintenance 
costs. 

DESIGN  OF  STRINGERS 

For  spans  varying  in  length  from  45  to  60  ft.  the  eco- 
nomical depth  of  stringer  is  about  5  ft.  For  uniformity 
of  appearance  and  details  it  is  of  course  desirable  to  keep 
the  depth  constant  as  far  as  possible.  As  the  number  of 
spans  exceeding  60  ft.  is  small,  5  ft.  was  adopted  as  the 
standard  depth,  except  for  spans  of  70  ft.  or  over. 

It  is  desirable  to  avoid  cover-plates  on  stringers  to  re- 
duce the  cutting  of  ties  over  rivet  heads.  In  addition  the 
top  cover-plate  must  be  extended  full  length  to  maintain 
a  uniform  distance  from  top  of  steel  to  base  of  rail.  With 


where  U  =  the  usual  allowable  unit-stress  and  H  =• 
the  depth  of  the  girder  in  inches. 

To  support  the  compression  flanges  of  stringers  and  pro- 
vide the  usual  truss  for  horizontal  forces,  lateral  bracing 
between  the  stringers  of  each  track  was  provided  as  shown 
in  Fig.  93,  with  cross-frames  at  intervals  varying  from 
12^4  to  20  ft.,  depending  on  the  span  lengths.  In  addi- 
tion lateral  bracing  was  placed  between  stringers  of  ad- 
jacent tracks  in  one  fixed  span  in  each  expansion  panel  in 
order  that  the  tractive  force  from  the  center  track  should 
be  transferred  to  the  columns  without  producing  lateral 
bending  on  the  cross-girder. 

Where  the  columns  are  outside  of  the  outside  stringer 
the  tractive  force  was  carried  to  the  column  by  a  strut 
from  the  outside  stringer  at  the  first  cross-frame.  The 
stress  to  be  transmitted  was  small,  requiring  only  two 


FIG.  95.     XEW  ELEVATED  STRUCTURE  WITH  COLUMNS  AT  CURB  (Xsw  UTRECHT  AVE.,  BROOKLYN  BOROUGH) 


70-ft.  span  and  o-t't.  depth,  either  cover-plates  or  flange 
angles  thicker  than  ~/s  in.  (which  must  be  drilled  from  the 
solid)  are  required.  Furthermore,  in  the  long  spans  the 
o-ft.  depth  is  uneconomical  and  the  deflections  are  exces- 
sive unless  the  allowable  flange  stress  is  reduced.  It 
seemed  necessary,  therefore,  to  sacrifice  appearance  to 
economy  and  good  practice  by  increasing  the  depth  to  ~.'i 
in.  and  78  in.  for  spans  70  ft.  long  or  over. 

In  cases  where  the  length  exceeded  twelve  times  the 
depth  of  stringer,  in  order  that  the  deflection  (in  inches) 
should  not  exceed  1/50  the  span  (in  feet),  the  allowable 
stress  was  reduced  to  the  value  given  by  the  following  for- 
mula : 


UH 


span  in  feet 


angles.  For  stiffness,  however,  latticed  struts  were  pro- 
vided, which  will  be  further  discussed  under  the  head  of 
columns.  Where  the  columns  are  between  the  stringers 
of  the  outside  tracks,  the  tractive  force  was  transmitted 
by  a  channel  riveted  to  the  bottom  flanges  of  the  string- 
ers, to  the  stiffeners  of  the  cross-girder  over  the  column 
and  thence  to  the  column. 

The  top  of  the  stringer  is  914  i".  above  the  top  of  the 
cross-girder,  so  that  the  top  flange  angles  extend  over  to 
the  center  of  the  cross-girder  and  are  supported  on  it  by 
seat-angle.-.  This  detail  is  arranged  to  provide  continu- 
ous support  for  the  ties,  to  make  unnecessary  special 
wide  spacing  at  the  flanges  of  cross-girders.  The  rivets 
in  these  seat-angles  are  intended  to  support  the  ends  of 
flange  angles  only  and  are  not  intended  to  produce  con- 
tinuity in  the  stringers — which  were  in  all  cases  designed 


[71] 


as  simple  spans.  Splicing  the  stringers  for  continuity 
was  considered,  but  was  abandoned  because  the  detail 
was  too  heavy  for  ultimate  economy,  and  continuity  over 
expansion  joints  was  impossible.  The  end-connection 
angles  were  set  against  the  webs  without  fillers  and  not 
carried  over  the  lower  flange  angles  to  a  bearing  on  the 
outstanding  leg,  as  this  was  considered  unnecessary.  A 


1.  With  the  direct  load  alone,  the  stress  per  square  inch 
should  not  exceed  that  allowed  by  the  Public  Service  Commis- 
sion formula 


S    = 


20,000 
V 


8000  r2 
with  a  maximum  of  14,000  Ib.   per  sq.in. 

2.  With  direct  load  combined  with  bending  in  one  direction 


\k-JLarcrng'-..  J 


6"x4" 

Y— 

16"WebP/r> 


MANHATTAN  ELUNES 
Sec+ion  A 


-vj 


' 1 

X 

CONTRACT  NO.  1 
Sec+ion  B 


15-1— 


x 

DUAL  SUBVMYSKSTCM 
Section   C 


DUAL  SUBW4Y SYSTEM 
Sec+ion    D 


PIG.  96.     COLUMN  SECTIONS  OF  ELEYATED 
KAILWAYS 


FIG.  97.     I-BEAM 
DISTORTION 


saving  of  nearly  $1  per  lin.ft.  of  structure  was  thereby 
effected. 

CROSS-GIRDEBS 

As  previously  described,  all  transverse  bending  stresses 
have  been  eliminated  so  far  as  practicable,  so  that  the 
design  of  the  cross-girder  followed  the  usual  practice  of 
girder  design.  For  column  spacing  of  47  ft.  4  in.,  a  6-ft. 
girder  was  used  generally,  while  a  5-ft.  girder  was  more 
economical  for  the  26-ft.  column  spacing.  Stiffeners 


Base   of  Rail 


only  the  stress  should  not  exceed  20,000  Ib.   per  sq.in.   on   the 
extreme  fiber. 

3.  With  direct  load  combined  with  bending  in  both  direc- 
tions at  the  same  time  the  stress  should  not  exceed  25,000  Ib. 
per  sq.in.  on  the  extreme  fiber. 

The  allowable  stress  is  increased  in  the  latter  cases  due 
to  the  infrequency  of  maximum  direct  load  and  maxi- 
mum horizontal  forces  in  both  directions  simultaneously. 

In  computing  the  bending  stress  in  the  column  due 
to  horizontal  forces  it  was  assumed  that  the  column  was 
fixed  both  top  and  bottom  (see  detail  of  base  in  Fig.  93). 


V  _    .    Street-  Surface 


Part     Side     Elevation  Cross— Sec+ion 

FIG.  98.    TOWER  CONSTRUCTION,  USED  FOR  HEIGHTS  OVER  30  FT. 


are  of  course  provided  over  the  column  to  transfer  the  re- 
action to  the  column.  Intermediate  stiffeners  were  pro- 
vided to  stiffen  the  girder  in  shipping  and  handling  only, 
as  the  stringers  when  connected  stiffen  the  web  sufficiently 
to  prevent  buckling. 

DESIGN  OF  COLUMNS 

The  columns  have  been  designed  for  a  combination  of 
direct  load  and  bending  stresses  due  to  wind,  centrifugal 
and  tractive  forces.  In  combining  the  direct  and  bending 
stresses  the  following  limits  were  adopted  as  giving  a 
safe  design : 


Four  114-in.  anchor  bolts  attached  to  the  base  of  the  col- 
umn by  seat-angles,  with  stiffeners  so  arranged  that  the 
nut  has  a  direct  bearing  over  the  stiffeners,  have  been  de- 
signed to  anchor  the  columns. 

With  the  columns  spaced  26  ft.,  longitudinal  bending 
stresses  are  transmitted  into  the  column  by  5x^2-in.  splice- 
bars  attached  to  the  stiffeners  on  the  cross-girder  and  to 
the  column  channels.  The  stiffeners  on  the  cross-girder 
over  the  columns  are  fixed  at  the  bottom  of  the  stringers 
by  the  channels  previously  described,  while  fixity  at  the 
top  is  secured  to  a  large  extent  by  the  transverse  stiffness 
of  the  top  flange  of  the  girder,  which  is  held  rigidly  by  the 


[72] 


adjacent  stringers,  less  than  2  ft.  from  the  column.  This 
bending  in  the  flange  occurs  at  a  point  where  the  vertical 
bending  stresses  are  small  and  does  not  therefore  over- 
stress  the  flange.  While  no  tests  of  this  detail  have  been 


Web  sp/iced  erf-  C.L.-for 
springers  over 
y       ' 


^c  „  c 

~     -fr.Spar. 


C.F. 


/4s  Figured 


r    5*.   5'  .  5^*54".   6",   6"     6 


ffiyef  spacing  -for  a  given  disfcmce  from  C.L.  of  stringers 
consran-f-for  a//  spans 

FIG.  99.    LATERAL  BEACING  AND  STEINGEK  RIVETING 

made,  it  is  believed  that  at  least  a  fair  degree  of  fixity 
in  the  column  longitudinally  is  obtained. 

When  the  columns  are  placed  beyond  the  outside  string- 
ers, in  place  of  the  splice-bars  just  described,  the  outside 
channel  of  the  column  is  extended  to  the  top  of  the  cross- 
girder  and  riveted  to  the  end  stiffeners,  transmitting  the 
longitudinal  bending  from  the  girder  to  the  column.  A 
latticed  strut  50  in.  deep  extends  from  the  stringer  at 
the  first  cross-frame  to  the  column  (see  Fig.  93  ;  the  strut 
is  also  shown  clearly  in  the  view,  Fig.  95).  With  this  depth 
it  is  believed  that  the  column  is  fixed  at  the  top. 

The  columns  and  the  cross-girder  being  connected  to 
form  a  rigid  portal,  the  wind  force  produces  a  bend- 
ing stress  in  the  cross-girder.  This,  however,  is  small, 
amounting  with  columns  spaced  47  ft.  4  in.  to  less  than 
\%,  and  with  columns  spaced  26  ft.  to  only  5%  of  the 
maximum  stresses  due  to  direct  load.  The  effect  of  wind 
on  the  cross-girder  has  therefore  been  neglected. 

In  selecting  the  type  of  column  no  section  was  consid- 
ered which  did  not  permit  inspection  and  painting,  thus 
eliminating  all  box  types  (see  Fig.  96). 

Section  A,  with  two  channels  laced,  was  used  exten- 
sively on  the  present  Manhattan  Ry.  Co.  elevated  lines. 
With  the  loads  for  which  the  columns  on  the  new  lines 
are  designed,  cover-plates  would  be  required  in  practically 
all  cases.  The  main  material  is  economically  placed,  but 
this  advantage  is  more  than  offset  by  the  loss  (so  far  as 
effective  section  is  concerned)  in  the  lacing  bars,  amount- 
ing to  about  12%  of  the  total  weight  of  the  column,  or 
15  to  18%  of  the  weight  of  main  material.  As  a  result 
the  column  is  not  so  economical  as  Section  C,  and  is  less 
satisfactory  as  to  details. 

The  elevated  extensions  of  the  present  subway.  Con- 
tract 1,  have  bulb-angle  columns,  Section  B,  usually  with- 


out cover-plates.  On  account  of  the  difficulty  of  obtaining 
bulb  angles  except  in  large  quantities,  and  also  because 
the  section  is  less  efficient  and  economical  than  a  channel- 
and-I-beam  column,  a  bulb-angle  type  has  not  been  used 
on  the  dual  system. 

Section  C  is  similar  to  Section  A,  except  that  the  chan- 
nels are  connected  by  an  I-beam  instead  of  by  lacing.  The 
beam  is  ineffective  in  lesisting  bending  about  axis  X-X. 
The  material  is  effectively  placed,  however,  for  resisting 
bending  about  axis  Y-Y  and  for  carrying  direct  load. 
For  the  elevated  loading  this  section  is  particularly  effi- 
cient and  economical.  The  material  in  the  column  with 
a  built-up  instead  of  a  rolled  I-beam,  Section  D,  is  slight- 
ly less  economical,  and  in  addition  there  are  two  extra 
lines  of  rivets.  The  I-beam-and-channel  type,  Section 
C,  was  therefore  adopted. 

In  fabricating  these  columns,  however,  some  difficulty 
has  developed.  The  beams  as  they  come  from  the  rolls 
are  invariably  slightly  warped,  as  shown  exaggerated  in 
Fig.  97.  When  the  channels  are  attached  it  has  been  diffi- 
cult to  avoid  a  wind  in  the  column.  This  trouble  devel- 
oped after  the  details  for  a  number  of  sections  were  com- 
pleted. To  avoid  this  difficulty  it  has  been  suggested  that 
on  future  work  the  I-beam-and-channel  column,  Section 
C,  be  abandoned  for  the  built-up  Section  D. 

Fig.  98  shows  the  typical  arrangement  of  tower  con- 
struction which  has  been  found  to  be  economical  where  the 
height  from  street  to  base  of  rail  exceeds  30  ft.  4  spac- 
ing of  35  ft.  between  bents  of  tower  span,  with  standard 
5-ft.  stringers,  proved  to  be  more  economical  than  a 
shorter  span  with  shallower  stringers,  and  in  addition  per- 
mitted greater  duplication  of  stringers  and  details  and 
maintained  a  uniform  appearance.  The  long  spans  are 
varied  to  suit  local  conditions,  a  length  of  about  60  ft. 
being  the  most  economical. 

In  order  to  duplicate  pieces,  details  have  been  standard- 
ized wherever  possible.  Stiffeners  and  flange  rivets  on  the 
stringers  and  the  arrangement  of  lateral  bracing  and 
cross-frames  are  shown  typically  in  Fig.  99.  Cross-frames 
were  spaced  at  intervals  not  exceeding  20  ft.  Stiffeners 
were  in  general  spaced  about  5  ft.  apart,  but  were 
placed  between  the  panel-points  of  horizontal  bracing 
except  at  cross-frames,  thus  avoiding  notching  lateral 
plates  at  intermediate  points. 

The  average  weight  of  steel,  including  stations,  on 
two  contracts  with  columns  spaced  47  ft.  4  in.  is  about 
1%  tons  (2250  Ib.)  per  lin.ft.  structure. 

The  design  of  the  subway  and  elevated  structures  of 
the  city-built  lines  of  the  dual  subway  system  is  made  by 
the  Public  Service  Commission's  engineering  staff,  of 
which  Alfred  Craven  is  Chief  Engineer ;  Robert  Ridgway, 
Engineer  of  Subway  Construction ;  D.  L.  Turner,  Deputy 
Engineer  of  Subway  Construction :  Sverre  Dahm.  Princi- 
pal Assistant  Engineer,  in  charge  of  design,  and  A.  I. 
Raisman,  Senior  Designing  Engineer.  The  design  of  the 
major  portion  of  the  elevated  lines  was  made  under  the  im- 
mediate supervision  of  the  writer. 


[73] 


BEWELEYLIBRARIES 


0057653510 


